CushieBlog

1. Introduction

Neuroendocrine tumors such as Pheochromocytoma and paraganglioma (PPGL) are an uncommon occurrence. The prevalence of PPGL has been estimated to be between (2–8)/1 million, with a population rate of 1:2500–1:6500 [1], and it is associated with symptoms such as headache, irregular heartbeats, profuse sweating, high blood pressure, nausea, vomiting, nervousness, irritability, and a sense of imminent mortality [2]. Hypercortisolism is also a rare disorder with an incidence of 5/1 million, <10 % of patients with hypercortisolism are caused by ectopic secretion of ACTH [3], and these are most commonly seen in APUD tumors such as small cell bronchopulmonary carcinoma, pancreatic islet carcinoma, medullary thyroid carcinoma, pheochromocytoma, and melanoma [4]. Tumors that secrete both ACTH and catecholamines are much rarer. Here, we present a case of ectopic ACTH-secreting pheochromocytoma with severe metabolic disorders. The case report is compliant with SCARE Guidelines [5].

2. Case report

The patient is a 46-year-old male who presented to our hospital with recurrent symptoms of pheochromocytoma. He reported that he experienced unexplained symptoms such as panic attacks, headache, sweating, nausea, vomiting, and a feeling of imminent death, which could be alleviated by rest. His blood pressure was around 160–220/110–120 mmHg, and he was taking oral antihypertensive drugs regularly, with poor control of his blood pressure. The patient was admitted with a body temperature of 36.7 °C, heart rate of 130 beats/min, respiratory rate of 20 cycles per minute, blood pressure of 138/88 mmHg, height of 175 cm, weight of 67 kg, Body Mass Index (BMI): 21.88, normal physical examination, emaciated body type, thin subcutaneous fat, self-reported weight loss of 20 kg within 10 months, and history of diabetes mellitus of >1 year.

Laboratory tests showed that the blood potassium levels were within the normal range, while the blood sugar and beta-hydroxybutyrate levels were elevated (Table 1). Hormonal analysis showed plasma levels of free catecholamine and its metabolites were much higher than normal, in addition to a severe excess of cortisol secretion with circadian rhythm disorders and elevated serum ACTH (Table 2). Small dose dexamethasone suppression test (1 mg) yielded cortisol levels of over 1750 nmol/L (negative: no decrease in blood cortisol), thus confirming the presence of ACTH-dependent hypercortisolism. The results of electrocardiogram, chest computerized tomography (CT), cardiac ultrasound and thyroid ultrasound showed no obvious abnormality. Enhanced CT of the adrenal glands (Fig. 1) revealed the presence of a right adrenal tumor measuring approximately 5.3 ∗ 4.7 cm. Despite undergoing cranial MRI, no pituitary lesion was detected, thereby ruling out the possibility of Cushing’s disease. The patient was further considered for possible ectopic ACTH syndrome and suspected ectopic ACTH-secreting pheochromocytoma.

Table 1. Laboratory test results.

Laboratory test	Result	Reference value	Unit
White blood cell	17.03	3.5–9.5	109/L
Red blood cell	5.06	3.8–5.1	1012/L
Hemoglobin	147	115–150	g/L
Platelets	206	125–350	109/L
Glucose	12.13	3.9–6.1	mmol/L
β-Hydroxybutyric acid	8.680	0–0.30	mmol/L
Creatinine	55.30	40–105	umol/L
Calcium	2.47	2.2–2.7	mmol/L
Phosphate	1.26	0.85–1.51	mmol/L
Potassium	3.66	3.5–5.5	mmol/L
Sodium	147.1	137–147	mmol/L

Table 2. The patient’s adrenal hormone results

Empty Cell	Preoperative	Postoperative	Reference value	Unit
Norepinephrine, free	11,900	118	217–1109	pg/ml
Adrenaline, free	3940	<24	<95	pg/ml
Dopamine	207	<18	<20	pg/ml
Methoxy norepinephrine	4130	87.80	<145	pg/ml
Methoxy adrenaline	1850	<12	<62	pg/ml
Adrenocorticotropic hormone (8:00)	544	10.60	7.2–63.3	pg/ml
Cortisol (8:00)	>1750	246.00	166–507	nmol/L
Adrenocorticotropic hormone (16:00)	647	33.50	–	pg/ml
Cortisol (16:00)	>1750	536.00	73.8–291	nmol/L
Adrenocorticotropic hormone (00:00)	566	–	–	pg/ml
Cortisol (00:00)	>1750	–		nmol/L
Renin	2.82	3.10	2.4–32.8	pg/ml
Aldosterone	81.51	73.56	16–160	pg/ml
Aldosterone/renin concentration ratio	28.90	23.73	0–25

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Fig. 1. Adrenal CT showed a 53 ∗ 47 mm mass in the right adrenal gland.

In response to the patient’s pheochromocytoma symptoms and improve preoperative preparation, we used α-blocker (Phenoxybenzamine 20 mg q8h) to lower blood pressure and increase blood volume, antihypertensive medication (nifedipine 30 mg q12h, olmesartan tablets 20 mg q12h) to assist in lowering blood pressure, and β-blocker (metoprolol 47.5 mg q12h) to control the heart rate. On the 4th day in hospital, the patient was lethargic and had weak limbs. Urgent blood workup showed severe hypokalemia (2.85 mmol/L) as well as hyperglycemia (10.26 mmol/L). Patient was transferred to intensive care to correct intractable hypokalemia and diabetic ketoacidosis.

After the patient was transferred to ICU, a deep vein cannulation was performed with intravenous potassium chloride supplementation, and the patient’s blood potassium was maintained at normal levels prior to surgery through a large amount of potassium supplementation (Fig. 2A). For diabetic ketoacidosis, insulin administration, rehydration, ketone elimination and other treatments were given and the amount of access was recorded, and it was found that the patient was polyuric, with the highest urine volume of 21,800 ml in a single day (Fig. 2B), and the amount of urine did not decrease by taking oral desmopressin tablets 0.1 mg bid.

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Fig. 2. Changes in blood potassium and urine volume during the patient’s hospitalization. A: Blood potassium level. B: Daily urine vlume.

Eventually, the patient underwent laproscopic right adrenal tumor resection. Intraoperative changes in blood pressure and heart rate are shown in Fig. 3. On day 1 after surgery, the morning (8:00) ACTH level was 10.60 pg/ml, antihypertensive medications were discontinued, and his blood pressure was 100–120/60–90 mmHg. The patient’s daily urine output and blood glucose gradually returned to normal levels after surgery. Pathology (Fig. 4): Adrenal pheochromocytoma with ACTH immunopositive staining, cellular heterogeneity was unremarkable, nuclear schizophrenic images were rare, no pericytes, choroidal invasion and necrosis were seen. The patient was discharged from the clinic in a satisfactory condition with adrenal insufficiency compensated by daily intake of Prednisone Acetate Tablets (20 mg), discontinued 6 months after surgery. No signs of recurrence were noted upon frequent follow-up examinations.

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Fig. 3. Changes in patient’s intraoperative blood pressure and heart rate.

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Fig. 4. Immunohistochemistry. A: hematoxylin and eosin staining B: ACTH.

3. Discussion

We share the management of a patient with ectopic ACTH-secreting pheochromocytoma with severe metabolic disturbances, where, in addition to the rare etiology, perioperative management of the clinical complications of catecholamines and hypercortisolism is very challenging [6].

Patients suffering from ectopic ACTH syndrome caused by pheochromocytoma commonly exhibit severe Cushing’s syndrome (CS), significant diabetes mellitus, hypertension, and hypokalemia [7]. Additionally, a retrospective study revealed that the majority of patients presented with Cushing’s syndrome [8], whereas another report indicated that only 30 % of patients presented with typical Cushing’s syndrome, but weight loss was frequently observed [9]. Our patient’s recent weight loss may be attributed to the body’s hypermetabolic condition caused by catecholamines. Recent reports claim that catecholamines directly reduce subcutaneous and visceral fat [10]. Rapid onset of cortisolism appears to be a feature of ACTH-secreting pheochromocytomas, because of the rapid onset of severe hypercortisolism, and our patient did not exhibit typical Cushing’s symptoms [8].

Despite the absence of typical Cushing-like symptoms, this patient displayed persistent hypokalemia, a prevalent metabolic manifestation of Cushing’s syndrome, particularly in ectopic ACTH syndrome, where hypokalemia is observed in 74 %–95 % of patients, in contrast to 10 % of patients with Cushing’s disease [11]. Glucocorticoids have the ability to interact with aldosterone receptors, resulting in specific aldosterone-like reactions, while ectopic ACTH syndrome typically generates a higher amount of cortisol compared to Cushing’s disease, ultimately causing more pronounced hypokalemia [7]. The perioperative management of patients with ACTH-secreting pheochromocytomas poses a significant challenge due to severe hypokalemia, and our patient’s potassium levels remained within the normal range through extensive central venous potassium supplementation, without the need for cortisol secretion inhibition medications.

The severity of hypertension in patients with ACTH-secreting pheochromocytomas seems to surpass that of patients with pheochromocytomas alone [12]. Hypercortisolism amplifies catecholamine-induced hypertension [13]. In the case of hypertension in patients with pheochromocytomas, alpha-blockers are favored for reducing blood pressure and enlarging blood volume, while for individuals whose blood pressure is not adequately managed with alpha-blockers alone, a combination of medications is recommended. Proper preoperative readiness for expanding the volume is crucial for a successful surgical procedure. Patients with ACTH-secreting pheochromocytoma have a greater prevalence and intensity of diabetes mellitus compared to those with pheochromocytoma alone [14], and our patient displayed a combination of severe diabetes mellitus and ketoacidosis. Insulin exhibits swift action and adaptable dosage, effectively averting hypoglycemia and effectively addressing hyperglycemia, rendering it the preferred medication for regulating blood glucose levels in individuals with ectopic CS [6].

Managing the water-electrolyte balance in this patient proved to be an arduous task, and the diabetes insipidus may have been one of the complications, with a maximum urine output of 21,800 ml in a single day (Fig. 2), and we hold the belief that the patient’s diabetes insipidus is caused by a range of factors, such as hypokalemia, hypercortisolism, and severe diabetes mellitus. Indeed, hypokalemia may cause renal impairment, which reduces the ability to concentrate urine and lack of response to antidiuretic hormone (ADH), leading to nephrogenic diabetes insipidus [15]. Cortisol increases renal plasma flow and glomerular filtration rate, and also inhibits the secretion of antidiuretic hormone, leading to neurogenic diabetes insipidus [16].

For hypercortisolism, surgery to target the cause is the first-line treatment, and surgical removal of primary tumor may lead to 40 % radical treatment and 80 % complete remission of ectopic ACTH syndrome [17].

4. Conclusion

Preoperative diagnosis and management of pheochromocytoma, an extremely rare cause of ectopic ACTH syndrome, is challenging. Proper preoperative recognition of complications of both hypercortisolism and catecholamines excess is the key to prevent the morbidity and mortality of an ACTH-producing pheochromocytoma. If diagnosed successfully and managed intensively, they are curable.

Consent

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Ethical approval

Shandong Provincial Hospital Affiliated to Shandong First Medical University does not require ethical approval for publication of case reports. Signed consent from the patient has been received.

Funding

No funding was received for this research.

Author contribution

Shangjian Li: study concept or design, data collection, data analysis or interpretation, writing the paper

Xudong Guo: study concept or design, data collection, data analysis or interpretation, writing the paper

Hanbo Wang: study concept or design, data analysis or interpretation

Ni Suo: study concept or design, data analysis or interpretation

Xiuqing Mi: study concept,data collection

Shaobo Jiang: study concept or design, data analysis or interpretation, writing the paper

Guarantor

Shangjian Li

Xudong Guo

Shaobo Jiang