Unveiling the Uncommon: Cushing’s Syndrome (CS) Masquerading as Severe Hypokalemia

Posted on July 2, 2024 by MaryO

Abstract

Cushing’s syndrome (CS) arises from an excess of endogenous or exogenous cortisol, with Cushing’s disease specifically implicating a pituitary adenoma and exaggerated adrenocorticotropic hormone (ACTH) production. Typically, Cushing’s disease presents with characteristic symptoms such as weight gain, central obesity, moon face, and buffalo hump.

This case report presents an unusual manifestation of CS in a 48-year-old male with a history of hypertension, where severe hypokalemia was the primary presentation. Initial complaints included bilateral leg swelling, muscle weakness, occasional shortness of breath, and a general feeling of not feeling well. Subsequent investigations revealed hypokalemia, metabolic alkalosis, and an abnormal response to dexamethasone suppression, raising concerns about hypercortisolism. Further tests, including 24-hour urinary free cortisol and ACTH testing, confirmed significant elevations. Brain magnetic resonance imaging (MRI) identified a pituitary macroadenoma, necessitating neurosurgical intervention.

This case underscores the rarity of CS presenting with severe hypokalemia, highlighting the diagnostic challenges and the crucial role of a collaborative approach in managing such intricate cases.

Introduction

Cushing’s syndrome (CS), characterized by excessive cortisol production, is well-known for its diverse and often conspicuous clinical manifestations. Cushing’s disease is a subset of CS resulting from a pituitary adenoma overproducing adrenocorticotropic hormone (ACTH), leading to heightened cortisol secretion. The classic presentation involves a spectrum of symptoms such as weight gain, central obesity, muscle weakness, and mood alterations [1].

Despite its classic presentation, CS can demonstrate diverse and atypical features, challenging conventional diagnostic paradigms. This case report sheds light on a rare manifestation of CS, where severe hypokalemia was the primary clinical indicator. Notably, instances of CS prominently manifesting through severe hypokalemia are scarce in the literature [1,2].

Through this exploration, we aim to provide valuable insights into the diagnostic intricacies of atypical CS presentations, underscore the significance of a comprehensive workup, and emphasize the collaborative approach essential for managing such uncommon hormonal disorders.

Case Presentation

A 48-year-old male with a history of hypertension presented to his primary care physician with complaints of bilateral leg swelling, occasional shortness of breath, dizziness, and a general feeling of malaise persisting for 10 days. The patient reported increased water intake and urinary frequency without dysuria. The patient was diagnosed with hypertension eight months ago. He experienced progressive muscle weakness over two months, hindering his ability to perform daily activities, including using the bathroom. The primary care physician initiated a blood workup that revealed severe hypokalemia with a potassium level of 1.3 mmol/L (reference range: 3.6 to 5.2 mmol/L), prompting referral to the hospital.

Upon admission, the patient was hypertensive with a blood pressure of 180/103 mmHg, a heart rate of 71 beats/minute, a respiratory rate of 18 breaths/minute, and an oxygen saturation of 96% on room air. Physical examination revealed fine tremors, bilateral 2+ pitting edema in the lower extremities up to mid-shin, abdominal distension with normal bowel sounds, and bilateral reduced air entry in the bases of the lungs on auscultation. The blood work showed the following findings (Table 1).

Parameter Result Reference Range
Potassium (K) 1.8 mmol/L 3.5-5.0 mmol/L
Sodium (Na) 144 mmol/L 135-145 mmol/L
Magnesium (Mg) 1.3 mg/dL 1.7-2.2 mg/dL
Hemoglobin (Hb) 15.5 g/dL 13.8-17.2 g/dL
White blood cell count (WBC) 13,000 x 103/µL 4.5 to 11.0 × 109/L
Platelets 131,000 x 109/L 150-450 x 109/L
pH 7.57 7.35-7.45
Bicarbonate (HCO3) 46 mmol/L 22-26 mmol/L
Lactic acid 4.2 mmol/L 0.5-2.0 mmol/L
Table 1: Blood work findings

In order to correct the electrolyte imbalances, the patient received intravenous (IV) magnesium and potassium replacement and was later transitioned to oral. The patient was also started on normal saline at 100 cc per hour. To further investigate the complaint of shortness of breath, the patient underwent a chest X-ray, which revealed bilateral multilobar pneumonia (Figure 1). He was subsequently treated with ceftriaxone (1 g IV daily) and clarithromycin (500 mg twice daily) for seven days.

A-chest-X-ray-revealing-(arrows)-bilateral-multilobar-pneumonia
Figure 1: A chest X-ray revealing (arrows) bilateral multilobar pneumonia

With persistent abdominal pain and lactic acidosis, a computed tomography (CT) scan abdomen and pelvis with contrast was conducted, revealing a psoas muscle hematoma. Subsequent magnetic resonance imaging (MRI) depicted an 8×8 cm hematoma involving the left psoas and iliacus muscles. The interventional radiologist performed drainage of the hematoma involving the left psoas and iliacus muscles (Figure 2).

Magnetic-resonance-imaging-(MRI)-depicting-an-8x8-cm-hematoma-(arrow)-involving-the-left-psoas-and-iliacus-muscles
Figure 2: Magnetic resonance imaging (MRI) depicting an 8×8 cm hematoma (arrow) involving the left psoas and iliacus muscles

In light of the concurrent presence of hypokalemia, hypertension, and metabolic alkalosis, there arose concerns about Conn’s syndrome, prompting consultation with endocrinology. Their recommended workup for Conn’s syndrome included assessments of the aldosterone-renin ratio and random cortisol levels. The results unveiled an aldosterone level below 60 pmol/L (reference range: 190 to 830 pmol/L in SI units) and a plasma renin level of 0.2 pmol/L (reference range: 0.7 to 3.3 mcg/L/hr in SI units). Notably, the aldosterone-renin ratio was low, conclusively ruling out Conn’s syndrome. The random cortisol level was notably elevated at 1334 nmol/L (reference range: 140 to 690 nmol/L).

Furthermore, a low-dose dexamethasone suppression test was undertaken due to the high cortisol levels. Following the administration of 1 mg of dexamethasone at 10 p.m., cortisol levels were measured at 9 p.m., 3 a.m., and 9 a.m. the following day. The results unveiled a persistently elevated cortisol level surpassing 1655 nmol/L, signaling an abnormal response to dexamethasone suppression and raising concerns about a hypercortisolism disorder, such as CS.

In the intricate progression of this case, the investigation delved deeper with a 24-hour urinary free cortisol level, revealing a significant elevation at 521 mcg/day (reference range: 10 to 55 mcg/day). Subsequent testing of ACTH portrayed a markedly elevated level of 445 ng/L, distinctly exceeding the normal reference range of 7.2 to 63.3 ng/L. A high-dose 8 mg dexamethasone test was performed to ascertain the source of excess ACTH production. The baseline serum cortisol levels before the high-dose dexamethasone suppression test were 1404 nmol/L, which decreased to 612 nmol/L afterward, strongly suggesting the source of excess ACTH production to be in the pituitary gland.

A CT scan of the adrenal glands ruled out adrenal mass, while an MRI of the brain uncovered a 1.3×1.3×3.2 cm pituitary macroadenoma (Figure 3), leading to compression of adjacent structures. Neurosurgery was consulted, and they recommended surgical removal of the macroadenoma due to the tumor size and potential complications. The patient was referred to a tertiary care hospital for pituitary adenoma removal.

Magnetic-resonance-imaging-(MRI)-of-the-brain-depicting-a-1.3x1.3x3.2-cm-pituitary-macroadenoma-(star)
Figure 3: Magnetic resonance imaging (MRI) of the brain depicting a 1.3×1.3×3.2 cm pituitary macroadenoma (star)

Discussion

CS represents a complex endocrine disorder characterized by excessive cortisol production. While the classic presentation of CS includes weight gain, central obesity, and muscle weakness, our case highlights an uncommon initial manifestation: severe hypokalemia. This atypical presentation underscores the diverse clinical spectrum of CS and the challenges it poses in diagnosis and management [1,2].

While CS typically presents with the classic symptoms mentioned above, severe hypokalemia as the initial manifestation is exceedingly rare. Hypokalemia in CS often results from excess cortisol-mediated activation of mineralocorticoid receptors, leading to increased urinary potassium excretion and renal potassium wasting. Additionally, metabolic alkalosis secondary to cortisol excess further exacerbates hypokalemia [3,4].

Diagnosing a case of Cushing’s disease typically commences with a thorough examination of the patient’s medical history and a comprehensive physical assessment aimed at identifying characteristic manifestations such as central obesity, facial rounding, proximal muscle weakness, and increased susceptibility to bruising. Essential to confirming the diagnosis are laboratory examinations, which involve measuring cortisol levels through various tests, including 24-hour urinary free cortisol testing, late-night salivary cortisol testing, and dexamethasone suppression tests. Furthermore, assessing plasma ACTH levels aids in distinguishing between pituitary-dependent and non-pituitary causes of CS. Integral to the diagnostic process are imaging modalities such as MRI of the pituitary gland, which facilitate the visualization of adenomas and the determination of their size and precise location [1-4].

Treatment for Cushing’s disease primarily entails surgical removal of the pituitary adenoma via transsphenoidal surgery, with the aim of excising the tumor and restoring normal pituitary function. In cases where surgical intervention is unsuitable or unsuccessful, pharmacological therapies employing medications such as cabergoline (a dopamine receptor agonist) or pasireotide (a somatostatin analogue) may be considered to suppress ACTH secretion and regulate cortisol levels. Additionally, radiation therapy, whether conventional or stereotactic radiosurgery, serves as a supplementary or alternative treatment approach to reduce tumor dimensions and mitigate ACTH production [5,6]. To assess the effectiveness of treatment, manage any problem, and assure long-term illness remission, diligent long-term follow-up and monitoring are essential. Collaborative multidisciplinary care involving specialists such as endocrinologists, neurosurgeons, and other healthcare professionals is pivotal in optimizing patient outcomes and enhancing overall quality of life [2,4].

The prognosis of CS largely depends on the underlying cause, stage of the disease, and efficacy of treatment. Early recognition and prompt intervention are essential for improving outcomes and minimizing long-term complications. Surgical resection of the adrenal or pituitary tumor can lead to remission of CS in the majority of cases. However, recurrence rates vary depending on factors such as tumor size, invasiveness, and completeness of resection [2,3]. Long-term follow-up with endocrinologists is crucial for monitoring disease recurrence, assessing hormonal function, and managing comorbidities associated with CS.

Conclusions

In conclusion, our case report highlights the rarity of severe hypokalemia as the initial presentation of CS. This unique presentation underscores the diverse clinical manifestations of CS and emphasizes the diagnostic challenges encountered in clinical practice. A multidisciplinary approach involving endocrinologists, neurosurgeons, and radiologists is essential for the timely diagnosis and management of CS. Early recognition, prompt intervention, and long-term follow-up are essential for optimizing outcomes and improving the quality of life for patients with this endocrine disorder.

References

  1. Nieman LK, Biller BM, Findling JW, Newell-Price J, Savage MO, Stewart PM, Montori VM: The diagnosis of Cushing’s syndrome: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2008, 93:1526-40. 10.1210/jc.2008-0125
  2. Newell-Price J, Bertagna X, Grossman AB, Nieman LK: Cushing’s syndrome. Lancet. 2006, 367:1605-17. 10.1016/S0140-6736(06)68699-6
  3. Torpy DJ, Mullen N, Ilias I, Nieman LK: Association of hypertension and hypokalemia with Cushing’s syndrome caused by ectopic ACTH secretion: a series of 58 cases. Ann N Y Acad Sci. 2002, 970:134-44. 10.1111/j.1749-6632.2002.tb04419.x
  4. Elias C, Oliveira D, Silva MM, Lourenço P: Cushing’s syndrome behind hypokalemia and severe infection: a case report. Cureus. 2022, 14:e32486. 10.7759/cureus.32486
  5. Fleseriu M, Petersenn S: Medical therapy for Cushing’s disease: adrenal steroidogenesis inhibitors and glucocorticoid receptor blockers. Pituitary. 2015, 18:245-52. 10.1007/s11102-014-0627-0
  6. Pivonello R, De Leo M, Cozzolino A, Colao A: The treatment of Cushing’s disease. Endocr Rev. 2015, 36:385-486. 10.1210/er.2013-1048

Filed under: Cushing's, pituitary, symptoms | Tagged: , , , , , , , , | Leave a comment »

Unveiling the Uncommon: Cushing’s Syndrome (CS) Masquerading as Severe Hypokalemia

Posted on April 26, 2024 by MaryO

Abstract

Cushing’s syndrome (CS) arises from an excess of endogenous or exogenous cortisol, with Cushing’s disease specifically implicating a pituitary adenoma and exaggerated adrenocorticotropic hormone (ACTH) production. Typically, Cushing’s disease presents with characteristic symptoms such as weight gain, central obesity, moon face, and buffalo hump.

This case report presents an unusual manifestation of CS in a 48-year-old male with a history of hypertension, where severe hypokalemia was the primary presentation. Initial complaints included bilateral leg swelling, muscle weakness, occasional shortness of breath, and a general feeling of not feeling well. Subsequent investigations revealed hypokalemia, metabolic alkalosis, and an abnormal response to dexamethasone suppression, raising concerns about hypercortisolism. Further tests, including 24-hour urinary free cortisol and ACTH testing, confirmed significant elevations. Brain magnetic resonance imaging (MRI) identified a pituitary macroadenoma, necessitating neurosurgical intervention.

This case underscores the rarity of CS presenting with severe hypokalemia, highlighting the diagnostic challenges and the crucial role of a collaborative approach in managing such intricate cases.

Introduction

Cushing’s syndrome (CS), characterized by excessive cortisol production, is well-known for its diverse and often conspicuous clinical manifestations. Cushing’s disease is a subset of CS resulting from a pituitary adenoma overproducing adrenocorticotropic hormone (ACTH), leading to heightened cortisol secretion. The classic presentation involves a spectrum of symptoms such as weight gain, central obesity, muscle weakness, and mood alterations [1].

Despite its classic presentation, CS can demonstrate diverse and atypical features, challenging conventional diagnostic paradigms. This case report sheds light on a rare manifestation of CS, where severe hypokalemia was the primary clinical indicator. Notably, instances of CS prominently manifesting through severe hypokalemia are scarce in the literature [1,2].

Through this exploration, we aim to provide valuable insights into the diagnostic intricacies of atypical CS presentations, underscore the significance of a comprehensive workup, and emphasize the collaborative approach essential for managing such uncommon hormonal disorders.

Case Presentation

A 48-year-old male with a history of hypertension presented to his primary care physician with complaints of bilateral leg swelling, occasional shortness of breath, dizziness, and a general feeling of malaise persisting for 10 days. The patient reported increased water intake and urinary frequency without dysuria. The patient was diagnosed with hypertension eight months ago. He experienced progressive muscle weakness over two months, hindering his ability to perform daily activities, including using the bathroom. The primary care physician initiated a blood workup that revealed severe hypokalemia with a potassium level of 1.3 mmol/L (reference range: 3.6 to 5.2 mmol/L), prompting referral to the hospital.

Upon admission, the patient was hypertensive with a blood pressure of 180/103 mmHg, a heart rate of 71 beats/minute, a respiratory rate of 18 breaths/minute, and an oxygen saturation of 96% on room air. Physical examination revealed fine tremors, bilateral 2+ pitting edema in the lower extremities up to mid-shin, abdominal distension with normal bowel sounds, and bilateral reduced air entry in the bases of the lungs on auscultation. The blood work showed the following findings (Table 1).

Parameter Result Reference Range
Potassium (K) 1.8 mmol/L 3.5-5.0 mmol/L
Sodium (Na) 144 mmol/L 135-145 mmol/L
Magnesium (Mg) 1.3 mg/dL 1.7-2.2 mg/dL
Hemoglobin (Hb) 15.5 g/dL 13.8-17.2 g/dL
White blood cell count (WBC) 13,000 x 103/µL 4.5 to 11.0 × 109/L
Platelets 131,000 x 109/L 150-450 x 109/L
pH 7.57 7.35-7.45
Bicarbonate (HCO3) 46 mmol/L 22-26 mmol/L
Lactic acid 4.2 mmol/L 0.5-2.0 mmol/L
Table 1: Blood work findings

In order to correct the electrolyte imbalances, the patient received intravenous (IV) magnesium and potassium replacement and was later transitioned to oral. The patient was also started on normal saline at 100 cc per hour. To further investigate the complaint of shortness of breath, the patient underwent a chest X-ray, which revealed bilateral multilobar pneumonia (Figure 1). He was subsequently treated with ceftriaxone (1 g IV daily) and clarithromycin (500 mg twice daily) for seven days.

A-chest-X-ray-revealing-(arrows)-bilateral-multilobar-pneumonia
Figure 1: A chest X-ray revealing (arrows) bilateral multilobar pneumonia

With persistent abdominal pain and lactic acidosis, a computed tomography (CT) scan abdomen and pelvis with contrast was conducted, revealing a psoas muscle hematoma. Subsequent magnetic resonance imaging (MRI) depicted an 8×8 cm hematoma involving the left psoas and iliacus muscles. The interventional radiologist performed drainage of the hematoma involving the left psoas and iliacus muscles (Figure 2).

Magnetic-resonance-imaging-(MRI)-depicting-an-8x8-cm-hematoma-(arrow)-involving-the-left-psoas-and-iliacus-muscles
Figure 2: Magnetic resonance imaging (MRI) depicting an 8×8 cm hematoma (arrow) involving the left psoas and iliacus muscles

In light of the concurrent presence of hypokalemia, hypertension, and metabolic alkalosis, there arose concerns about Conn’s syndrome, prompting consultation with endocrinology. Their recommended workup for Conn’s syndrome included assessments of the aldosterone-renin ratio and random cortisol levels. The results unveiled an aldosterone level below 60 pmol/L (reference range: 190 to 830 pmol/L in SI units) and a plasma renin level of 0.2 pmol/L (reference range: 0.7 to 3.3 mcg/L/hr in SI units). Notably, the aldosterone-renin ratio was low, conclusively ruling out Conn’s syndrome. The random cortisol level was notably elevated at 1334 nmol/L (reference range: 140 to 690 nmol/L).

Furthermore, a low-dose dexamethasone suppression test was undertaken due to the high cortisol levels. Following the administration of 1 mg of dexamethasone at 10 p.m., cortisol levels were measured at 9 p.m., 3 a.m., and 9 a.m. the following day. The results unveiled a persistently elevated cortisol level surpassing 1655 nmol/L, signaling an abnormal response to dexamethasone suppression and raising concerns about a hypercortisolism disorder, such as CS.

In the intricate progression of this case, the investigation delved deeper with a 24-hour urinary free cortisol level, revealing a significant elevation at 521 mcg/day (reference range: 10 to 55 mcg/day). Subsequent testing of ACTH portrayed a markedly elevated level of 445 ng/L, distinctly exceeding the normal reference range of 7.2 to 63.3 ng/L. A high-dose 8 mg dexamethasone test was performed to ascertain the source of excess ACTH production. The baseline serum cortisol levels before the high-dose dexamethasone suppression test were 1404 nmol/L, which decreased to 612 nmol/L afterward, strongly suggesting the source of excess ACTH production to be in the pituitary gland.

A CT scan of the adrenal glands ruled out adrenal mass, while an MRI of the brain uncovered a 1.3×1.3×3.2 cm pituitary macroadenoma (Figure 3), leading to compression of adjacent structures. Neurosurgery was consulted, and they recommended surgical removal of the macroadenoma due to the tumor size and potential complications. The patient was referred to a tertiary care hospital for pituitary adenoma removal.

Magnetic-resonance-imaging-(MRI)-of-the-brain-depicting-a-1.3x1.3x3.2-cm-pituitary-macroadenoma-(star)
Figure 3: Magnetic resonance imaging (MRI) of the brain depicting a 1.3×1.3×3.2 cm pituitary macroadenoma (star)

Discussion

CS represents a complex endocrine disorder characterized by excessive cortisol production. While the classic presentation of CS includes weight gain, central obesity, and muscle weakness, our case highlights an uncommon initial manifestation: severe hypokalemia. This atypical presentation underscores the diverse clinical spectrum of CS and the challenges it poses in diagnosis and management [1,2].

While CS typically presents with the classic symptoms mentioned above, severe hypokalemia as the initial manifestation is exceedingly rare. Hypokalemia in CS often results from excess cortisol-mediated activation of mineralocorticoid receptors, leading to increased urinary potassium excretion and renal potassium wasting. Additionally, metabolic alkalosis secondary to cortisol excess further exacerbates hypokalemia [3,4].

Diagnosing a case of Cushing’s disease typically commences with a thorough examination of the patient’s medical history and a comprehensive physical assessment aimed at identifying characteristic manifestations such as central obesity, facial rounding, proximal muscle weakness, and increased susceptibility to bruising. Essential to confirming the diagnosis are laboratory examinations, which involve measuring cortisol levels through various tests, including 24-hour urinary free cortisol testing, late-night salivary cortisol testing, and dexamethasone suppression tests. Furthermore, assessing plasma ACTH levels aids in distinguishing between pituitary-dependent and non-pituitary causes of CS. Integral to the diagnostic process are imaging modalities such as MRI of the pituitary gland, which facilitate the visualization of adenomas and the determination of their size and precise location [1-4].

Treatment for Cushing’s disease primarily entails surgical removal of the pituitary adenoma via transsphenoidal surgery, with the aim of excising the tumor and restoring normal pituitary function. In cases where surgical intervention is unsuitable or unsuccessful, pharmacological therapies employing medications such as cabergoline (a dopamine receptor agonist) or pasireotide (a somatostatin analogue) may be considered to suppress ACTH secretion and regulate cortisol levels. Additionally, radiation therapy, whether conventional or stereotactic radiosurgery, serves as a supplementary or alternative treatment approach to reduce tumor dimensions and mitigate ACTH production [5,6]. To assess the effectiveness of treatment, manage any problem, and assure long-term illness remission, diligent long-term follow-up and monitoring are essential. Collaborative multidisciplinary care involving specialists such as endocrinologists, neurosurgeons, and other healthcare professionals is pivotal in optimizing patient outcomes and enhancing overall quality of life [2,4].

The prognosis of CS largely depends on the underlying cause, stage of the disease, and efficacy of treatment. Early recognition and prompt intervention are essential for improving outcomes and minimizing long-term complications. Surgical resection of the adrenal or pituitary tumor can lead to remission of CS in the majority of cases. However, recurrence rates vary depending on factors such as tumor size, invasiveness, and completeness of resection [2,3]. Long-term follow-up with endocrinologists is crucial for monitoring disease recurrence, assessing hormonal function, and managing comorbidities associated with CS.

Conclusions

In conclusion, our case report highlights the rarity of severe hypokalemia as the initial presentation of CS. This unique presentation underscores the diverse clinical manifestations of CS and emphasizes the diagnostic challenges encountered in clinical practice. A multidisciplinary approach involving endocrinologists, neurosurgeons, and radiologists is essential for the timely diagnosis and management of CS. Early recognition, prompt intervention, and long-term follow-up are essential for optimizing outcomes and improving the quality of life for patients with this endocrine disorder.

References

  1. Nieman LK, Biller BM, Findling JW, Newell-Price J, Savage MO, Stewart PM, Montori VM: The diagnosis of Cushing’s syndrome: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2008, 93:1526-40. 10.1210/jc.2008-0125
  2. Newell-Price J, Bertagna X, Grossman AB, Nieman LK: Cushing’s syndrome. Lancet. 2006, 367:1605-17. 10.1016/S0140-6736(06)68699-6
  3. Torpy DJ, Mullen N, Ilias I, Nieman LK: Association of hypertension and hypokalemia with Cushing’s syndrome caused by ectopic ACTH secretion: a series of 58 cases. Ann N Y Acad Sci. 2002, 970:134-44. 10.1111/j.1749-6632.2002.tb04419.x
  4. Elias C, Oliveira D, Silva MM, Lourenço P: Cushing’s syndrome behind hypokalemia and severe infection: a case report. Cureus. 2022, 14:e32486. 10.7759/cureus.32486
  5. Fleseriu M, Petersenn S: Medical therapy for Cushing’s disease: adrenal steroidogenesis inhibitors and glucocorticoid receptor blockers. Pituitary. 2015, 18:245-52. 10.1007/s11102-014-0627-0
  6. Pivonello R, De Leo M, Cozzolino A, Colao A: The treatment of Cushing’s disease. Endocr Rev. 2015, 36:385-486. 10.1210/er.2013-1048

Filed under: Cushing's, symptoms | Tagged: , , , , , | Leave a comment »

Olfactory Neuroblastoma Causing Cushing’s Syndrome Due to the Ectopic Adrenocorticotropic Hormone (ACTH) Secretion

Posted on April 17, 2024 by MaryO

Abstract

Cushing’s syndrome is a constellation of features occurring due to high blood cortisol levels. We report a case of a 47-year-old male with a history of recurrent olfactory neuroblastoma (ONB). He presented with bilateral lower limb weakness and anosmia and was found to have Cushing’s syndrome due to high adrenocorticotropic hormone (ACTH) levels from an ectopic source, ONB in this case. Serum cortisol and ACTH levels declined after tumor removal.

Introduction

Olfactory neuroblastoma (ONB), or esthesioneuroblastoma, is a rare malignancy arising from neuroepithelium in the upper nasal cavity. It represents approximately 2% of all nasal passage tumors, with an incidence of approximately 0.4 per 2.5 million individuals [1]. ONB shares similar histological features with small round blue cell neoplasms of the nose. Ectopic hormone secretion is a very rare feature associated with these tumors. Five-year overall survival is reported to be between 60% and 80% [2,3]. The age distribution is either in the fifth to sixth decade of life [4,5], or in the second and sixth decades [6].

Features of Cushing’s syndrome (moon face, buffalo hump, central obesity hypertension, fragile skin, easy bruising, fatigue, muscle weakness) are due to high blood cortisol levels [7]. It can be either primary (cortisol-secreting adrenal tumor), secondary (adrenocorticotropic hormone (ACTH)-secreting pituitary tumor, also called Cushing disease), or ectopic ACTH secretion (from a non-pituitary source). All three types share similar features [8].

Ectopic ACTH syndrome (EAS) is due to an extra pituitary tumor, producing ACTH. It accounts for 12-17% of Cushing’s syndrome cases [9]. Most cases of EAS-producing tumors are in the lungs, mediastinum, neuroendocrine tumors of the gastrointestinal tract, and pheochromocytomas [9]. Ectopic ACTH secretion from an ONB is very rare. As of 2015, only 18 cases were reported in the literature [10]. Here, we report such a case.

Case Presentation

Our patient is a 47-year-old Bangladeshi male, with a history of recurrent ONB that was resected twice in the past (transsphenoidal resection in 2016 and 2019) with adjuvant radiotherapy, no chemotherapy was given. He also had diabetes mellitus type 1 (poorly controlled) and hypertension. He presented with bilateral lower limb weakness, anosmia, decreased oral intake, loss of taste for one week, and bilateral submandibular swelling that increased in size gradually over the past two years. There was no history of fever, cough, abdominal pain, or exposure to sick contacts. The patient reported past episodes of similar symptoms, but details are unclear. The patient’s family history is positive for diabetes mellitus type 1 in both parents. Lab tests in the emergency department showed hypokalemia and hyperglycemia as detailed in Table 1. He was admitted for further workup of the above complaints.

Test Patient Results Reference Range Unit Status
Hemoglobin 14.7 13-17 g/dL Normal
White blood cell (WBC) 17.9 4-10 10*9/L High
Neutrophils 15.89 2-7 10*9/L High
Lymphocytes 1.07 1-3 10*9/L Normal
Sodium 141 136-145 mmol/L Normal
Potassium 2.49 3.5-5.1 mmol/L Low (Panic)
Chloride 95 98-107 mmol/L Low
Glucose 6.52 4.11-5.89 mmol/L Elevated
C-reactive protein (CRP) 0.64 Less than 5 mg/L Normal
Erythrocyte sedimentation rate (ESR) 2 0-30 mm/h Normal
Creatinine 73 62-106 µmol/L Normal
Uric acid 197 202.3-416.5 µmol/L Normal
Alanine aminotransferase (ALT) 33.2 0-41 U/L Normal
Aspartate aminotransferase (AST) 18.6 0-40 U/L Normal
International Normalised Ratio (INR) 1.21 0.8-1.2 sec High
Prothrombin time (PT) 15.7 12.3-14.7 sec High
Lactate dehydrogenase (LDH) 491 135-225 U/L High
Thyroid-stimulating hormone (TSH) 0.222 0.27-4.20 mIU/L Low
Adrenocorticotropic hormone (ACTH) 106 ≤50 ng/L Elevated
Cortisol (after dexamethasone suppression) 1750 Morning hours (6-10 am): 172-497 nmol, Afternoon hours (4-8 pm): 74.1-286 nmol nmol/L Elevated (failure of suppression)
24-hour urine cortisol (after dexamethasone suppression) 5959.1 <120 nmol/24 hrs nmol/24hr Elevated (failure of suppression)
Table 1: Results of blood test at the time of hospitalization. Hypokalemia and high values of adrenocorticotropic hormone and cortisol were confirmed.

On examination, the patient’s vital signs were as follows: blood pressure was 154/77 mmHg, heart rate of 60 beats per minute, respiratory rate was 18 breaths per minute, oxygen saturation of 98% on room air, and a temperature of 36.7°C. The patient had a typical Cushingoid appearance with a moon face, buffalo hump, purple striae on the abdomen, central obesity, and hyperpigmentation of the skin. Submandibular lymph nodes were enlarged bilaterally. The examination of the submandibular lymph nodes showed a firm, fixed mass extending from the angle of the mandible to the submental space on the left side. Neurological examination showed weakness in both legs bilaterally (strength 3/5) and anosmia (checked by orthonasal smell test). The rest of the neurological exam was normal.

Laboratory findings revealed (in Table 1) a marked hypokalemia of 2.49 mmol/L and hyperglycemia of 6.52 mmol/L. The serum cortisol level was elevated at 1587 nmol/L. Serum ACTH levels were raised at 106 ng/L (normal value ≤50 ng/L). Moreover, the high-dose dexamethasone suppression test failed to lower the serum ACTH levels and serum and urine cortisol. Serum cortisol level after the suppression test was 1750 nmol/L, while 24-hour urine cortisol after the test was 5959.1 nmol/24hr. Serum ACTH levels after the test also remained high at 100mg/L. This indicated failure of ACTH suppression by high-dose dexamethasone, which points towards ectopic ACTH production. Other blood tests (complete blood count, liver function tests) were insignificant.

A computed tomography scan with contrast (CT scan) of the chest, abdomen, and pelvis, with a special focus on the adrenals, was negative for any malignancy or masses. CT scan of the neck showed bilaterally enlarged submandibular lymph nodes and an enlarged right lobe of the thyroid with nodules. Fine needle aspiration (FNA) of the thyroid nodules revealed a benign nature. Magnetic resonance imaging (MRI) of the brain showed a contrast-enhancing soft tissue lesion (18x18x10mm) in the midline olfactory groove area with extension into the frontal dura and superior sagittal sinus, suggesting recurrence of the previous ONB. There was evidence of previous surgery also. The pituitary gland was normal (Figures 1–2).

A-brain-MRI-(T1-weighted;-without-contrast;-sagittal-plane)-shows-a-soft-tissue-lesion-located-in-the-midline-olfactory-groove-area.-Dural-surface-with-extension-into-anterior-frontal-dura.
Figure 1: A brain MRI (T1-weighted; without contrast; sagittal plane) shows a soft tissue lesion located in the midline olfactory groove area. Dural surface with extension into anterior frontal dura.

MRI: Magnetic resonance imaging

A-brain-MRI-(T2-weighted;-without-contrast;-axial-plane)-shows-a-soft-tissue-lesion-located-in-the-midline-olfactory-groove-area.
Figure 2: A brain MRI (T2-weighted; without contrast; axial plane) shows a soft tissue lesion located in the midline olfactory groove area.

MRI: Magnetic resonance imaging

Octreotide scintigraphy showed three focal abnormal uptakes in the submandibular cervical nodes. Additionally, there was a moderate abnormal uptake at the midline olfactory groove with bilateral extension (Figure 3).

Whole-body-octreotide-scan-(15-mCi-99mTc-Octreotide-IV)-demonstrates-three-focal-abnormal-uptakes:-the-largest-(5.2-x-2.4-cm)-in-the-left-submandibular-region,-and-two-smaller-ones-on-the-right,-suggestive-of-lymph-node-uptake.-Additional-abnormal-uptake-was-seen-along-the-midline-of-the-olfactory-groove-region-with-bilateral-extension.-No-other-significant-abnormal-uptake-was-identified.
Figure 3: Whole-body octreotide scan (15 mCi 99mTc-Octreotide IV) demonstrates three focal abnormal uptakes: the largest (5.2 x 2.4 cm) in the left submandibular region, and two smaller ones on the right, suggestive of lymph node uptake. Additional abnormal uptake was seen along the midline of the olfactory groove region with bilateral extension. No other significant abnormal uptake was identified.

On microscopic examination, an excisional biopsy after the transcranial resection surgery of the frontal skull base tumor showed nests and lobules of round to oval cells with clear cytoplasm, separated by vascular and hyalinized fibrous stroma (Figures 4A–4B). Tumor cells show mild to moderate nuclear pleomorphism, and fine chromatin (Figure 4C). A fibrillary neural matrix is also present. Some mitotic figures can be seen. Immunohistochemical stains revealed positive staining for synaptophysin (Figure 4D) and chromogranin (Figure 4E). Stains for CK (AE1/AE3), CD45, Desmin, and Myogenin are negative. Immunostaining for ACTH was focally positive (Figure 4F), while the specimen of the cervical lymph nodes showed the same staining, indicating metastases. The cytomorphologic and immunophenotypic features observed are consistent with a Hyams grade II ONB, with ectopic ACTH production.

Histopathological-and-immunohistochemical-findings-of-olfactory-neuroblastoma.
Figure 4: Histopathological and immunohistochemical findings of olfactory neuroblastoma.

A (100x magnification) and B (200x magnification) – hematoxylin and eosin (H-E) staining shows cellular nests of round blue cells separated by hyalinized stroma. C (400x magnification) – nuclei show mild to moderate pleomorphism with fine chromatin. D (100x magnification) – an immunohistochemical stain for synaptophysin shows diffuse, strong cytoplasmic positivity within tumor cells. E (200x magnification) – tumor cells are positive for chromogranin. F (400x magnification) – ACTH cytoplasmic expression in tumor cells.

ACTH: adrenocorticotropic hormone

For his resistant hypokalemia, he had to be given intravenous (IV) and oral potassium chloride (KCL) repeatedly. The patient underwent transcranial resection of the frontal skull base tumor. The patient received cefazolin for seven days, and hydrocortisone for four days. After transcranial resection, his cortisol level decreased to 700 nmol/L. Furthermore, ACTH dropped, and serum potassium also normalized. Subsequently, the patient was transferred to the intensive care unit (ICU) for meticulous monitoring and continued care. In the ICU, the patient developed one episode of a generalized tonic-clonic seizure, which aborted spontaneously, and the patient received phenytoin and levetiracetam to prevent other episodes. A right-sided internal jugular vein and left transverse sinus thrombosis were also developed and treated with enoxaparin sodium. Following surgery, his low potassium levels improved, resulting in an improvement in his limb weakness. His other symptoms also gradually improved after surgery. Three weeks following the primary tumor resection, he underwent bilateral neck dissection with right hemithyroidectomy, for removal of the metastases. The patient opted out of chemotherapy and planned for an international transfer to his home country for further management. Other treatments that he received during hospitalization were ceftriaxone, azithromycin, and Augmentin®. Insulin was used to manage his diabetes, perindopril to regulate his blood pressure, and spironolactone to increase potassium retention. Omeprazole was administered to prevent GI bleeding and heartburn/gastroesophageal reflux disease relief after discharge.

Discussion

ONB was first described in 1924, and it is a rare neuroectodermal tumor that accounts for 2% of tumors affecting the nasal cavity [11]. Even though ONB has a good survival rate, long-term follow-up is necessary due to the disease’s high recurrence rate [2]. ONB recurrence has been approximated to range between 30% and 60% after successful treatment of the primary tumor [12]. Recurrent disease is usually locoregional and tends to have a long interval to relapse with a mean of six years [12]. The first reported case of ectopic ACTH syndrome caused by ONB was in 1987 by M Reznik et al., who reported a 48-year-old woman with ONB who developed a Cushing-like syndrome 28 months before her death [13].

The occurrence of Cushing’s syndrome due to ectopic ACTH can occur either in the initial tumor or even years later during its course or after recurrence [3,6,9,14]. Similar to the case of Abe et al. [3], our patient also presented with muscle weakness due to hypokalemia, which is a feature of Cushing’s syndrome. Hypokalemia is present at diagnosis in 64% to 86% of cases of EAS and is resistant to treatment [9,14], as seen in our case. In our patient, the exact time of development of Cushing’s syndrome could not be ascertained due to the non-availability of previous records. However, according to the patient, he started developing abdominal obesity, pigmentation, and buffalo hump in 2021 about two years after his second surgery for ONB.

The distinction between pituitary ACTH and ectopic ACTH involves utilizing CT/MRI of the pituitary, corticotropin-releasing hormone (CRH) stimulation test with petrosal sinus blood sampling, high dose dexamethasone suppression test, and checking serum K+ (more commonly low in ectopic ACTH) [2,15,16]. In our case, a CRH stimulation test was not available but CT/MRI brain, dexamethasone test, low serum potassium, plus the postoperative fall in cortisol levels, all pointed towards an ectopic ACTH source.

Conclusions

In conclusion, this case highlights the rare association between ONB and ectopic ACTH syndrome, which developed after tumor recurrence. The patient’s unique presentation of bilateral lower limb weakness and hypokalemia can cause diagnostic challenges, emphasizing the need for comprehensive diagnostic measures. Surgical intervention proved crucial, with postoperative cortisol values becoming normal, highlighting the efficacy of this approach. The occurrence of ectopic ACTH production in ONB patients, although very rare, is emphasized, so that healthcare professionals who deal with these tumors are aware of this complication. This report contributes valuable insights shedding light on the unique ONB manifestation causing ectopic ACTH syndrome. The ongoing monitoring of the patient’s clinical features will further enrich the understanding of the course of this uncommon phenomenon in the medical literature.

References

  1. Thompson LD: Olfactory neuroblastoma. Head Neck Pathol. 2009, 3:252-9. 10.1007/s12105-009-0125-2
  2. Abdelmeguid AS: Olfactory neuroblastoma. Curr Oncol Rep. 2018, 20:7. 10.1007/s11912-018-0661-6
  3. Abe H, Suwanai H, Kambara N, et al.: A rare case of ectopic adrenocorticotropic hormone syndrome with recurrent olfactory neuroblastoma. Intern Med. 2021, 60:105-9. 10.2169/internalmedicine.2897-19
  4. Yin Z, Wang Y, Wu Y, et al.: Age distribution and age-related outcomes of olfactory neuroblastoma: a population-based analysis. Cancer Manag Res. 2018, 10:1359-64. 10.2147/CMAR.S151945
  5. Platek ME, Merzianu M, Mashtare TL, Popat SR, Rigual NR, Warren GW, Singh AK: Improved survival following surgery and radiation therapy for olfactory neuroblastoma: analysis of the SEER database. Radiat Oncol. 2011, 6:41. 10.1186/1748-717X-6-41
  6. Elkon D, Hightower SI, Lim ML, Cantrell RW, Constable WC: Esthesioneuroblastoma. Cancer. 1979, 44:3-1087. 10.1002/1097-0142(197909)44:3<1087::aid-cncr2820440343>3.0.co;2-a
  7. Nieman LK, Biller BM, Findling JW, Newell-Price J, Savage MO, Stewart PM, Montori VM: The diagnosis of Cushing’s syndrome: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2008, 93:1526-40. 10.1210/jc.2008-0125
  8. Chabre O: Cushing syndrome: physiopathology, etiology and principles of therapy [Article in French]. Presse Med. 2014, 43:376-92. 10.1016/j.lpm.2014.02.001
  9. Isidori AM, Lenzi A: Ectopic ACTH syndrome. Arq Bras Endocrinol Metabol. 2007, 51:1217-25. 10.1590/s0004-27302007000800007
  10. Kunc M, Gabrych A, Czapiewski P, Sworczak K: Paraneoplastic syndromes in olfactory neuroblastoma. Contemp Oncol (Pozn). 2015, 19:6-16. 10.5114/wo.2015.46283
  11. Finlay JB, Abi Hachem R, Jang DW, Osazuwa-Peters N, Goldstein BJ: Deconstructing olfactory epithelium developmental pathways in olfactory neuroblastoma. Cancer Res Commun. 2023, 3:980-90. 10.1158/2767-9764.CRC-23-0013
  12. Ni G, Pinheiro-Neto CD, Iyoha E, et al.: Recurrent esthesioneuroblastoma: long-term outcomes of salvage therapy. Cancers (Basel). 2023, 15:1506. 10.3390/cancers15051506
  13. Reznik M, Melon J, Lambricht M, Kaschten B, Beckers A: Neuroendocrine tumor of the nasal cavity (esthesioneuroblastoma). Apropos of a case with paraneoplastic Cushing’s syndrome [Article in French]. Ann Pathol. 1987, 7:137-42.
  14. Kadoya M, Kurajoh M, Miyoshi A, et al.: Ectopic adrenocorticotropic hormone syndrome associated with olfactory neuroblastoma: acquirement of adrenocorticotropic hormone expression during disease course as shown by serial immunohistochemistry examinations. J Int Med Res. 2018, 46:4760-8. 10.1177/0300060517754026
  15. Clotman K, Twickler MTB, Dirinck E, et al.: An endocrine picture in disguise: a progressive olfactory neuroblastoma complicated with ectopic Cushing syndrome. AACE Clin Case Rep. 2017, 3:278-83. 10.4158/EP161729.CR
  16. Chung YS, Na M, Ku CR, Kim SH, Kim EH: Adrenocorticotropic hormone-secreting esthesioneuroblastoma with ectopic Cushing’s syndrome. Yonsei Med J. 2020, 61:257-61. 10.3349/ymj.2020.61.3.257

From https://www.cureus.com/articles/226080-olfactory-neuroblastoma-causing-cushings-syndrome-due-to-the-ectopic-adrenocorticotropic-hormone-acth-secretion-a-case-report#!/

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Ectopic Cushing’s Syndrome From a Corticotropin-Releasing Hormone-Secreting Medullary Thyroid Carcinoma: a Rare Pitfall af Inferior Petrosal Sinus Sampling

Posted on October 27, 2023 by MaryO

Abstract

Summary

This case report describes a rare presentation of ectopic Cushing’s syndrome (CS) due to ectopic corticotropin-releasing hormone (CRH) production from a medullary thyroid carcinoma (MTC).

The patient, a 69-year-old man, presented with symptoms of muscle weakness, facial plethora, and easy bruising.

An inferior petrosal sinus sampling test (IPSS) demonstrated pituitary adrenocorticotrophic hormone (ACTH) secretion, but a whole-body somatostatin receptor scintigraphy (68Ga-DOTATOC PET/CT) revealed enhanced uptake in the right thyroid lobe which, in addition to a grossly elevated serum calcitonin level, was indicative of an MTC. A 18F-DOPA PET/CT scan supported the diagnosis, and histology confirmed the presence of MTC with perinodal growth and regional lymph node metastasis.

On immunohistochemical analysis, the tumor cell stained positively for calcitonin and CRH but negatively for ACTH. Distinctly elevated plasma CRH levels were documented. The patient therefore underwent thyroidectomy and bilateral adrenalectomy.

This case shows that CS caused by ectopic CRH secretion may masquerade as CS due to a false positive IPSS test. It also highlights the importance of considering rare causes of CS when diagnostic test results are ambiguous.

Learning points

  • Medullary thyroid carcinoma may secrete CRH and cause ectopic CS.
  • Ectopic CRH secretion entails a rare pitfall of inferior petrosal sinus sampling yielding a false positive test.
  • Plasma CRH measurements can be useful in selected cases.

Background

The common denominator of Cushing’s syndrome (CS) is autonomous hypersecretion of cortisol (1) and it is subdivided into ACTH-dependent and ACTH-independent causes. The majority of CS cases are ACTH-dependent (80–85%) with a pituitary corticotroph tumor as the most prevalent cause (Cushing’s disease), and less frequently an ectopic ACTH-producing tumor (2). The gold standard method to ascertain the source of ACTH secretion in CS patients is inferior petrosal sinus sampling (IPSS) with measurement of plasma ACTH levels in response to systemic corticotropin-releasing hormone (CRH) stimulation (3). The IPSS has a very high sensitivity and specificity of 88–100% and 67–100%, respectively (4), but pitfalls do exist, including the rare ectopic CRH-producing tumor, which may yield a false positive test result (3). Here, we describe a very rare case masquerading as CS including a positive IPSS test.

Case presentation

A 69-year-old man presented at a local hospital with a 6-month history of progressive fatigue, muscle weakness and wasting, easy bruising, facial plethora, and fluid retention. His serum potassium level was 2.6 mmol/L (reference range: 3.5–4.2 mmol/L) without a history of diuretics use. His previous medical history included spinal stenosis, benign prostatic hyperplasia, and hypertension. An electromyography showed no sign of polyneuropathy and an echocardiography showed no signs of heart failure with an ejection fraction of 55%. MRI of the spine revealed multiple compression fractures, and the patient underwent spinal fusion and decompression surgery; during this admission he was diagnosed with type 2 diabetes (HbA1c: 55 mmol/mol). After spine surgery, the patient developed a pulmonary embolism and initiated treatment with rivaroxaban.

Establishing the diagnosis of ACTH-dependent CS

Six months after his spine surgery, the patient was referred to the regional department of endocrinology for osteoporosis management. Blood tests revealed a low serum testosterone level with non-elevated luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels (Table 1). An overnight 1 mg dexamethasone suppression test was positive with a morning cortisol level of 254 nmol/L and three consecutive 24-h urinary cortisol levels were markedly elevated with mean level of ≈600 nmol/24 h (reference range: 12–150 nmol/24 h). A single plasma ACTH was 37 ng/L (Table 1).

Table 1Baseline endocrine assessment.

Parameters Patient’s values Reference range
ACTH, ng/L 37 7–64
UFC, nmol/day 588 12–150
Urinary cortisol, nmol/L 600 171–536
OD, nmol/L 254 <50
Free testosterone, nmol/L 0.061 0.17–0.59
HbA1c, mmol/mol 55 <48
FSH, IU/L 7.4 1.2–15.8
LH, IU/L 2.2 1.7–8.6

ACTH, adrenocorticotropin; FSH, follicle-stimulating hormone; IU, international units; LH, luteinizing hormone; OD, plasma cortisol levels after a 1 mg overnight dexamethasone suppression test; UFC, urine free cortisol hormone.

Differential diagnostic tests

The patient was referred to a tertiary center for further examinations. Ketoconazole treatment was started to alleviate the consequences of hypercortisolism. A pituitary MRI revealed an intrasellar microtumor with a maximal diameter of 6 mm and an IPSS was ordered. A whole-body somatostatin receptor scintigraphy (68Ga-DOTATOC PET/CT) was also performed to evaluate the presence of a potential neuroendocrine tumor. This revealed multiple areas of enhanced uptake including the right thyroid lobe and cervical lymph nodes in the neck (with CT correlates), as well as in the duodenum (with no CT correlate). Concomitantly, a grossly elevated serum calcitonin level of 528 pmol/L (reference range <2.79 pmol/L) was measured.

Subsequently, the IPSS revealed pituitary ACTH secretion with a central-to-peripheral ACTH ratio >3 (Table 2). The right petrosal sinus was not successfully catheterized; thus, lateralization could not be determined.

To corroborate the diagnosis MTC, a 18F-DOPA PET/CT scan (FDOPA) was performed (5), which showed pathologically enhanced uptake in the right thyroid lobe and regional lymph nodes (Fig. 1). An ultrasound-guided core needle biopsy from the thyroid nodule was inconclusive; however, the patient underwent total thyroidectomy and regional lymph node resection, from which histology confirmed the diagnosis of disseminated MTC. Standard replacement with levothyroxine, calcium, and vitamin D was initiated. A blood sample was collected, and genomic DNA was extracted. The DNA analysis for RET germline mutation was negative.

Figure 1View Full Size
Figure 1
18F-DOPA PET/CT scan with pathologically enhanced uptake in the right thyroid lobe (large blue arrow on the left side) and regional lymph nodes (small blue arrows).

Citation: Endocrinology, Diabetes & Metabolism Case Reports 2023, 3; 10.1530/EDM-23-0057

Table 2Results from the inferior petrosal sinus sampling.*

Time (min) Left IPSS Peripheral L/P
-5 42 36 1.2
-1 116 33 3.5
2 120 32 3.8
5 209 28 7.5
7 180 43 4.2
10 529 34 15.6
15 431 37 11.6

*Data represents ACTH levels in ng/L. IPSS Inferior petrosal sampling ACTH Adrenocorticotropin hormone CRH Corticotropin-releasing hormone, L/P Ratio of left (L) inferior petrosal sinus to peripheral venous ACTH concentrations.

Pathology

Total thyroidectomy and bilateral cervical lymph node dissection (level six and seven) were performed. Macroscopic evaluation of the right thyroid lobe revealed a 24 mm, irregular solid yellow tumor. Microscopically the tumor showed an infiltrating architecture with pseudofollicles and confluent solid areas. Calcification was prominent, but no amyloid deposition was seen. The tumor cells were pleomorphic with irregular nuclei and heterogenic chromatin structure. No mitotic activity or necrosis was observed. On immunohistochemical analysis, the tumor cells expressed thyroid transcription factor 1 and stained strongly for carcinoembryonic antigen and calcitonin; tumor cells were focally positive for cytokeratin 19. The tumor was completely negative for ACTH, thyroid peroxidase, and the Hector Battifora mesothelial-1 antigen. Further analysis revealed positive immunostaining for CRH (Fig. 2). The Ki-67 index was very low (0–1%), indicating a low cellular proliferation. Molecular testing for somatic RET mutation was not performed.

Figure 2View Full Size
Figure 2
Histopathological findings and immunohistochemical studies of MTC. (A) Microscopic features of medullary thyroid carcinoma. (B) Polygonal tumor cells (hematoxylin and eosin, ×40). (C) Tumor cells stain for calcitonin (×20). (D) Immunohistochemical stain (×400) for CRH showing cells being positive (brown). (E) Pituitary tissue from healthy control staining positive for ACTH in comparison to (F) ACTH-negative cells MTC tissue from the patient (×20).

Citation: Endocrinology, Diabetes & Metabolism Case Reports 2023, 3; 10.1530/EDM-23-0057

No malignancy was found in the left thyroid lobe and there was no evidence of C-cell hyperplasia. Regional lymph node metastasis was found in 13 out of 15 nodes with extranodal extension.

Outcome and follow-up

Follow-up

Serum calcitonin levels declined after neck surgery but remained grossly elevated (118 pmol/L 3 weeks post surgery) and cortisol levels remained high. Ketoconazole treatment was poorly tolerated and not sufficiently effective. Plasma levels of CRH were measured by a competitive-ELISA kit (EKX-KIZI6R-96 Nordic BioSite), according to the instructions provided by the manufacturer. The intra- and interassay %CV (coefficient of variability) were below 8% and 10%, respectively, and the assay sensitivity was 1.4 pg/mL. The plasma CRH was distinctly elevated compared to in-house healthy controls both before and after thyroid surgery (Fig. 3).

Figure 3View Full Size
Figure 3
Plasma CRH levels before and after total thyroidectomy compared to three healthy controls.

Citation: Endocrinology, Diabetes & Metabolism Case Reports 2023, 3; 10.1530/EDM-23-0057

The patient subsequently underwent uneventful bilateral laparoscopic adrenalectomy followed by standard replacement therapy with hydrocortisone and fludrocortisone. The symptoms and signs of his CS gradually subsided. Pathology revealed bilateral cortical hyperplasia as expected.

The patient continues follow-up at the Department of Oncology and the Department of Endocrinology and Internal Medicine. At 13-month follow-up, 68Ga-DOTATOC shows residual disease with pathologically enhanced uptake in two lymph nodes, whereas the previously described focal DOTATOC uptake in the duodenum was less pronounced (still no CT correlate). Serum calcitonin was 93 pmol/L at the 13-month follow-up.

Discussion

Diagnostic challenges remain in the distinction between pituitary and ectopic ACTH-dependent CS, and several diagnostic tools are used in combination, none of which is infallible, including IPSS (6). Our case and others illustrate that ectopic CRH secretion may yield a false positive IPSS test result (3). Measurement of circulating CRH levels is relevant if an ectopic CRH producing tumor is suspected, but the assay is not routinely available in clinical practice (Lynnette K Nieman M. Measurement of ACTH, CRH, and other hypothalamic and pituitary peptides https://www.uptodate.com/contents/measurement-of-acth-crh-and-other-hypothalamic-and-pituitary-peptides: UpToDate; 2019). In our case, the presence of elevated plasma CRH levels after thyroidectomy strengthened the indication for bilateral adrenalectomy.

The most common neoplasm causing ectopic CS is small-cell lung cancer, whereas MTC accounts for 2–8% of ectopic cases (7). The development of CS in relation to MTC is generally associated with advanced disease and poor prognosis of an otherwise relatively indolent cancer (8), and the clinical progression of CS is usually rapid, why an early recognition and rapid control of hypercortisolemia and MTC is necessary to decrease morbidity and mortality (7, 9). Our case does have residual disease; however, he remains progression-free with stable and relatively low calcitonin levels within 1-year follow-up.

Only a very limited number of cases of ectopic tumors with either combined ACTH and CRH secretion or isolated CRH secretion have been reported, with ectopic CRH secretion accounting for less than 1% of CS (9).

An ACTH- or CRH-producing tumor can be difficult to localize and may include gastric ACTH/CRH-secreting neuroendocrine tumors (9). In our case, the 68Ga-DOTATOC identified a possible duodenal site, in addition to the MTC, but an upper gastrointestinal endoscopy revealed no pathological findings and there was no CT correlate. Thus, we concluded that the most likely and sole source of ectopic CRH was the MTC and its metastases.

To our knowledge, no official guidelines for managing ectopic ACTH-dependent CS have been established. In a recent publication by Alba et al. (10), the authors demonstrated a clinical algorithm (The Mount Sinai Clinical Pathway, MSCP) and recommendation for the management of CS due to ectopic ACTH secretion.

Essentially, our approach in this particular case followed these recommendations, including source location by CT and 68Ga-DOTATATE PET/CT imaging, acute management with ketoconazole, and finally, bilateral adrenalectomy as curative MTC surgery was not possible. In retrospect, performance of the IPSS could be questioned in view of the MTC diagnosis. In real time, however, a pituitary MRI performed early in the diagnostic process revealed a microadenoma, which prompted the IPSS. In parallel, a somatostatin receptor scintigraphy (68Ga-DOTATOC PET/CT) was also done, which raised the suspicion of an MTC.

Conclusion

We report a very rare case of an ectopic CS caused by a CRH-secreting MTC. Although IPSS has stood the test of time in the differential diagnosis of ACTH-dependent CS, this case illustrates a rare pitfall.

Declaration of interest

The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.

Funding

This research did not receive any specific grant from any funding agency in the public, commercial, or not-for-profit sector.

Patient consent

Written informed consent for publication of their clinical details was obtained from the patient.

Author contribution statement

JOJ and MJO are the physicians responsible for the patient. LR performed the thyroidectomy and bilateral adrenalectomy. SHM and SLA assessed and reassessed the histopathology and the immunohistochemical analysis. MB measured plasma CRH. VM, JOJ, and MJO drafted the manuscript. All authors contributed to critical revision of the manuscript.

References

Filed under: Cancer, Cushing's, Diagnostic Testing, Rare Diseases, symptoms | Tagged: , , , , , | Leave a comment »

Sparsely Granulated Corticotroph Pituitary Macroadenoma Presenting with Pituitary Apoplexy Resulting in Remission of Hypercortisolism

Posted on April 27, 2022 by MaryO
https://doi.org/10.1016/j.aace.2022.04.003Get rights and content
Under a Creative Commons license
Open access

Highlights

• We describe a rare case of a patient with a sparsely granulated corticotroph pituitary macroadenoma with pituitary apoplexy who underwent transsphenoidal resection resulting in remission of hypercortisolism.
• Corticotroph adenomas are divided into densely granulated, sparsely granulated and Crooke’s cell tumors.
• macroadenomas account for 7-23% of patients with pituitary corticotroph adenomas
• Sparsely granulated corticotroph tumors are associated with longer duration of Cushing disease prior to diagnosis, larger tumor size at diagnosis, decreased immediate remission rate, increased proliferative marker Ki-67 and increased recovery time of hypothalamic-pituitary-adrenal axis after surgery.
• Granulation pattern is an important clinicopathological distinction impacting the behavior and treatment outcomes of pituitary corticotroph adenomas

Abstract

Background

/Objective: Pituitary corticotroph macroadenomas, which account for 7% to 23% of corticotroph adenomas, rarely present with apoplexy. The objective of this report is to describe a patient with a sparsely granulated corticotroph tumor (SGCT) presenting with apoplexy and remission of hypercortisolism.

Case Report

A 33-year-old male presented via ambulance with sudden onset of severe headache and nausea/vomiting. Physical exam revealed bitemporal hemianopsia, diplopia from right-sided third cranial nerve palsy, abdominal striae, facial plethora, dorsal and supraclavicular fat pad. Magnetic resonance imaging (MRI) demonstrated a 3.2 cm mass arising from the sella turcica with hemorrhage compressing the optic chiasm, extension into the sphenoid sinus and cavernous sinus. Initial investigations revealed plasma cortisol of 64.08 mcg/dL (Reference Range (RR), 2.36 – 17.05). He underwent emergent transsphenoidal surgery. Pathology was diagnostic of SGCT. Post-operatively, cortisol was <1.8ug/dL (RR, 2.4 – 17), adrenocorticotropic hormone (ACTH) 36 pg/mL (RR, 0 – 81), thyroid stimulating hormone (TSH) 0.07 uIU/mL (RR, 0.36 – 3.74), free thyroxine 1 ng/dL (RR, 0.8 – 1.5), luteinizing hormone (LH) <1 mIU/mL (RR, 1 – 12), follicle stimulating hormone (FSH) 1 mIU/mL (RR, 1 – 12) and testosterone 28.8 ng/dL (RR, 219.2 – 905.6) with ongoing requirement for hydrocortisone, levothyroxine, testosterone replacement and continued follow-up.

Discussion

Corticotroph adenomas are divided into densely granulated, sparsely granulated and Crooke’s cell tumors. Sparsely granulated pattern is associated with larger tumor size and decreased remission rate after surgery.

Conclusion

This report illustrates a rare case of hypercortisolism remission due to apoplexy of a SGCT with subsequent central adrenal insufficiency, hypothyroidism and hypogonadism.

Keywords

pituitary apoplexy
pituitary macroadenoma
pituitary tumor
sparsely granulated corticotroph tumor
Cushing disease

Introduction

The incidence of Cushing Disease (CD) is estimated to be between 0.12 to 0.24 cases per 100,00 persons per year1,2. Of these, 7-23% are macroadenomas (>1 cm)3, 4, 5. Pituitary apoplexy is a potentially life-threatening endocrine and neurosurgical emergency which occurs due to infarction or hemorrhage in the pituitary gland. Apoplexy occurs most commonly in non-functioning macroadenomas with an estimated prevalence of 6.2 cases per 100,000 persons and incidence of 0.17 cases per 100,00 persons per year6. Corticotroph macroadenoma presenting with apoplexy is uncommon with only a handful of reports in the literature7. We present a case of a sparsely granulated corticotroph (SGCT) which presented with apoplexy leading to remission of hypercortisolism and subsequent central adrenal insufficiency.

Case Presentation

A 33-year-old male who was otherwise healthy and not on any medications presented to a community hospital with sudden and severe headache accompanied by hypotension, nausea, vomiting, bitemporal hemianopsia and diplopia. Computed Tomography (CT) scan of the brain demonstrated a hyperattenuating 2.0 cm x 2.8 cm x 1.5 cm mass at the sella turcica with extension into the right cavernous sinus and encasement of the right internal carotid arteries (Figure 1A). He was transferred to a tertiary care center for neurosurgical management with endocrinology consultation post-operatively.

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Figure 1. hyperattenuating 2.0 cm x 2.8 cm x 1.5 cm mass at the sella turcica on unenhanced CT (A); MRI demonstrated a 1.9 cm x 3.2 cm x 2.4 cm heterogeneous mass on T1 (B) and T2-weighted imaging (C) showing small hyperintense areas in solid part of the sella mass with flattening of the optic chiasm, remodeling/dehiscence of the floor of the sella and extending into the right cavernous sinus with at least partial encasement of the ICA

In retrospect, he reported a 3-year history of ongoing symptoms of hypercortisolism including increased central obesity, dorsal and supraclavicular fat pad, facial plethora, abdominal purple striae, easy bruising, fatigue, decreased libido and erectile dysfunction. Notably, at the time of presentation he did not have a history of diabetes, hypertension, osteoporosis, fragility fractures or proximal muscle weakness. He fathered 2 children previously. His physical examination was significant for Cushingoid facies, facial plethora, dorsal and supraclavicular fat pads and central obesity with significant axillary and abdominal wide purple striae (Figure 2). Neurological examination revealed bitemporal hemianopsia, right third cranial nerve palsy with ptosis and impaired extraocular movement. The fourth and sixth cranial nerves were intact as was the rest of his neurological exam. These findings were corroborated by Ophthalmology.

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Figure 2. Representative images illustrating facial plethora (A); abdominal striae (B, C); supraclavicular fat pad (D); dorsal fat pad (E)

Initial laboratory data at time of presentation to the hospital included elevated plasma cortisol of 64.08ug/dL (RR, 2.36 – 17.05), ACTH was not drawn at the time of presentation, normal TSH 0.89 mIU/L (RR, 0.36 – 3.74), free thyroxine 0.91ng/dL (RR, 0.76 – 1.46), evidence of central hypogonadism with low total testosterone 28.8 ng/dL (RR, 219.2 – 905.6) and inappropriately normal luteinizing hormone (LH) 1mIU/mL (RR, 1 – 12) and follicle stimulating hormone (FSH) 3mIU/mL (RR, 1 – 12), low prolactin <1 ng/mL (RR, 3 – 20), and normal insulin growth factor – 1 (IGF–1) 179ng/mL (RR, 82 – 242).

A pituitary gland dedicated MRI was performed to further characterize the mass, which re-demonstrated a 1.9 cm x 3.2 cm x 2.4 cm heterogenous mass at the sella turcica extending superiorly and flattening the optic chiasm, remodeling of the floor of the sella and bulging into the sphenoid sinus and extending laterally into the cavernous sinus with encasement of the right internal carotid artery (ICA). As per the radiologist’s diagnostic impression, this appearance was most in keeping with a pituitary macroadenoma with apoplexy (Figure 1B – C).

The patient underwent urgent TSS and decompression with no acute complications. Pathological examination of the pituitary adenoma showed features characteristic of sparsely granulated corticotroph pituitary neuroendocrine tumor (adenoma)8, with regional hemorrhage and tumor necrosis (apoplexy). The viable tumor exhibited a solid growth pattern (Figure 3A), t-box transcription factor (T-pit) nuclear immunolabeling (Figure 3B), diffuse cytoplasmic CAM5.2 (low molecular weight cytokeratin) immunolabeling (Figure 3C), and regional weak to moderate intense granular cytoplasmic ACTH immuno-staining (Figure 3D). The tumor was immuno-negative for: pituitary-specific positive transcription factor 1 (Pit-1) and steroidogenic factor 1 (SF-1) transcription factors, growth hormone, prolactin, TSH, FSH, LH, estrogen receptor-alpha, and alpha-subunit. Crooke hyalinization was not identified in an adjacent compressed fragment of non-adenomatous anterior pituitary tissue. Ki-67 immunolabeling showed a 1.5% proliferative index (11 of 726 nuclei).

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Figure 3. Hematoxylin phloxine saffron staining showing adenoma with solid growth pattern (A); immunohistochemical staining showing T-pit reactivity of tumor nuclei (B); diffuse cytoplasmic staining for cytokeratin CAM5.2 (C); and regional moderately intense granular cytoplasmic staining for ACTH (D). Scale bar = 20 μm

Post-operatively, he developed transient central diabetes insipidus requiring desmopressin but resolved on discharge. His postoperative cortisol was undetectable, ACTH 36 pg/mL (RR, 0 – 81), TSH 0.07 mIU/mL (RR, 0.36 – 3.74), free thyroxine 1 ng/dL (RR, 0.8 – 1.5), LH <1mIU/mL (RR, 1 – 12), FSH 1 mIU/mL (RR, 1 – 12) and testosterone 28.8 ng/dL (RR, 219.2 – 905.6) (Table 1 and Figure 4). One month later, he reported 15 pounds of weight loss and a 5-inch decrease in waist circumference. He also noted a reduction in the dorsal and supraclavicular fat pads, facial plethora, and Cushingoid facies as well as fading of the abdominal stretch marks. His visual field defects and right third cranial nerve palsy resolved on follow up with ophthalmology post-operatively. Repeat MRI six months post-operatively showed minor residual soft tissue along the floor of the sella. He is being followed by Neurosurgery, Ophthalmology, and Endocrinology for monitoring of disease recurrence, visual defects, and management of hypopituitarism.

Table 1. Pre- and post-operative hormonal panel

POD -1 POD 0 POD1 POD2 POD3 POD16 6 -9 months Comments
Cortisol(2.4 – 17 ug/dL) 64↓ 32↓ 11↓ <1.8↓ <1.8↓ 1.8↓ HC started POD3 post bloodwork
ACTH(0 – 81 pg/mL) 41↓ 36↓ 28↓ 13↓
TSH(0.36 – 3.74 uIU/mL) 0.89 0.43 0.12↓ 0.07↓ 0.05↓ 0.73
Thyroxine, free(0.8 – 1.5 ng/dL) 0.9 0.9 1.1 1 2.1↑ 1 Levothyroxine started POD4
LH(1 – 12 miU/mL) 1↓ <1↓ 1↓ 3
FSH(1 – 12 mIU/mL) 3↓ 1↓ 1↓ 3
Testosterone(219.2 – 905.6 ng/dL) 28.8↓ <20↓ 175.9↓ Testosterone replacement started as outpatient
Testosterone, free(160 – 699 pmol/L) <5.8↓ 137↓
IGF-1(82 – 242 ng/mL) 179 79
GH(fasting < 6 mIU/L) 4.5 <0.3
Prolactin(3 – 20 ng/mL) <1↓ <1↓

POD, postoperative day; HC, hydrocortisone; ACTH, adrenocorticotropic hormone; TSH, thyroid stimulating hormone; LH, luteinizing Hormone; FSH, follicle stimulating hormone; IGF-1, insulin like growth factor – 1; GH, growth hormone

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Figure 4. Trend of select pituitary hormonal panel with key clinical events denoted by black arrows.

Discussion

Microadenomas account for the majority of corticotroph tumors, but 7% – 23% of patients are diagnosed with a macroadenoma3, 4, 5. It is even rarer for a corticotroph macroadenoma to present with apoplexy with only a handful of case reports or series in the literature7. Due to its rarity, appropriate biochemical workup on presentation, such as including an ACTH with the blood work, may be omitted especially if the patient is going for emergent surgery. In this case, the undetectable prolactin can reflect loss of anterior pituitary function and also suggest a functioning corticotroph adenoma due to the inhibitory effect of long term serum glucocorticoids on prolactin secretion9. After undergoing TSS, the patient developed central adrenal insufficiency, hypothyroidism and hypogonadism requiring hormone replacement. Presumably, the development of adrenal insufficiency demonstrated the remission of hypercortisolism as a result of apoplexy and/or TSS. The ACTH remains detectable likely representing residual tumor that was not obliterated by apoplexy nor excised by TSS given it location near the carotid artery and cavernous sinus. The presence of adrenal insufficiency in the setting of detectable ACTH is not contradictory as the physiological hypothalamic-pituitary-adrenal axis has been suppressed by the long-term pathological production of ACTH. IGF-1 and prolactin also failed to recover post-operatively. In CD where the production of IGF-1 and prolactin are attenuated by elevated cortisol, it would then be expected that IGF-1 and prolactin recover after hypercortisolism remission. However, the absence of this observation in our case is likely a sequalae of the apoplexy and extensive surgery leading to pituitary hypofunction.

We also want to highlight features of the pre-operative radiographical findings which can provide valuable insight into the subsequent histology. Previous literature has shown that, on T2-weight MRI, silent corticotroph adenomas are strongly correlated with characteristic a multimicrocystic appearance while nonfunctional gonadotroph macroadenomas are not correlated with this MRI finding10. The multimicrocystic appearance is described as small hyperintense areas with hyperintense striae in the solid part of the tumor (Figure 1C)10. This is an useful predictive tool for silent corticotroph adenomas with a sensitivity of 76%, specificity of 95% and a likelihood ratio of 15.310.

The ability to distinguish between silent corticotroph macroadenoma and other macroadenomas is important for assessing rate of remission and recurrence risk. In 2017, the WHO published updated classification for pituitary tumors. In this new classification, corticotroph adenomas are further divided into densely granulated, sparsely granulated and Crooke’s cell tumors11. DGCT are intensely Periodic Acid Schiff (PAS) stain positive and exhibit strong diffuse pattern of ACTH immunoreactivity, whereas SGCT exhibit faintly positive PAS alongside weak focal ACTH immunoreactivity4,12. Crooke’s cell tumors are characterized by Crooke’s hyaline changes in more than 50% of the tumor cells4. In the literature, SGCT account for an estimated 19-29% of corticotroph adenomas13, 14, 15. The clinicopathological relevance of granulation pattern in corticotroph tumors was unclear until recently.

In multiple studies examining granulation pattern and tumor size, SGCT were statistically larger13,15,16. Hence, we suspect that many of the previously labelled silent corticotroph macroadenomas in the literature were SGCT. The traditional teaching of CD has been “small tumor, big Cushing and big tumor, small Cushing” which reflects the inverse relationship between tumor size and symptomatology17. This observation appears to hold true as Doğanşen et al. found a trend towards longer duration of CD in SGCT of 34 months compared to 26 months in DGCT based on patient history13,17. It has been postulated that the underlying mechanism of the inverse relationship between tumor size and symptomatology is impaired processing of proopiomelanocortin resulting in less effective secretion of ACTH in corticotroph macroadenomas3. Doğanşen et al. also found that the recurrence rate was doubled for SGCT, while Witek et al. showed that SGCT were less likely to achieve remission postoperatively13,16.

Similar to other cases of SGCT, the diagnosis was only arrived retrospective after pathological confirmation10. Interestingly, the characteristic Crooke’s hyaline change of surrounding non-adenomatous pituitary tissue was not observed as one would expect in a state of prolonged glucocorticoid excess in this case. Although classically described, the absence of this finding does not rule out CD. As evident in a recent retrospective study where 10 out of 144 patients with CD did not have Crooke’s hyaline change18. In patients without Crooke’s hyaline change, the authors found a lower remission rate of 44.4% compared to 73.5% in patients with Crooke’s hyaline change. Together with the detectable post-operative ACTH, sparsely granulated pattern and absence of Crooke’s hyaline change in surrounding pituitary tissue, the risk of recurrence is increased. These risk factors emphasize the importance of close monitoring to ensure early detection of recurrence.

Declaration of Interests

☒ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

☐The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:

Conclusion

We present a case of a sparsely granulated corticotroph macroadenoma presenting with apoplexy leading to remission of hypercortisolism and development of central adrenal insufficiency, hypothyroidism and hypogonadism requiring hormone replacement.

References

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