Neurosurgical treatment of Cushing disease in pediatric patients: case series and review of literature

 2018 Nov 28. doi: 10.1007/s00381-018-4013-5. [Epub ahead of print]

Abstract

AIM:

Pituitary adenomas are rare in childhood in contrast with adults. Adrenocorticotropic hormone (ACTH)-secreting adenomas account for Cushing’s disease (CD) which is the most common form of ACTH-dependent Cushing’s syndrome (CS). Treatment strategies are generally based on data of adult CD patients, although some difficulties and differences exist in pediatric patients. The aim of this study is to share our experience of 10 children and adolescents with CD.

PATIENTS AND METHOD:

Medical records, images, and operative notes of 10 consecutive children and adolescents who underwent transsphenoidal surgery for CD between 1999 and 2014 in Cerrahpasa Faculty of Medicine were retrospectively reviewed. Mean age at operation was 14.8 ± 4.2 years (range 5-18). The mean length of symptoms was 24.2 months. The mean follow-up period was 11 years (range 4 to 19 years).

RESULTS:

Mean preoperative cortisol level was 23.435 μg/dl (range 8.81-59.8 μg/dl). Mean preoperative ACTH level was 57.358 μg/dl (range 28.9-139.9 μg/dl). MR images localized microadenoma in three patients (30%), macroadenoma in four patients (40%) in our series. Transsphenoidal microsurgery and endoscopic transsphenoidal surgery were performed in 8 and 2 patients respectively. Remission was provided in 8 patients (80%). Five patients (50%) met remission criteria after initial operations. Three patients (30%) underwent additional operations to meet remission criteria.

CONCLUSION:

Transsphenoidal surgery remains the mainstay therapy for CD in pediatric patients as well as adults. It is an effective treatment option with low rate of complications. Both endoscopic and microscopic approaches provide safe access to sella and satisfactory surgical results.

KEYWORDS:

Cushing’s disease; Endoscopic pituitary surgery; Pediatric; Transsphenoidal microsurgery

PMID:
30488233
DOI:
10.1007/s00381-018-4013-5

Full Text

Mutations in Two Genes, USP48 and BRAF, Linked to Cushing’s Disease

Mutations in USP48 and BRAF genes contribute to the overproduction of adrenocorticotropin (ACTH) hormone by the pituitary gland and consequent development of Cushing’s disease, a study shows, linking these genes to the disease for a first time.

The study, “Identification of recurrent USP48 and BRAF mutations in Cushing’s disease,” published in the journal Nature Communications, also identified a possible treatment for patients with BRAF-related mutations.

Cushing’s disease is a condition characterized by excessive cortisol levels that, if left untreated, can lead to serious cardiovascular problems, infections, and mood disorders. It usually arises from benign pituitary tumors that produce too much of ACTH hormone, which in turn stimulates the adrenal glands to secrete cortisol.

It is still not clear why some people develop these tumors, but studies have pointed to mutations in the USP8 gene as a possible cause. They are present in 35%–62% of all tumor cases, and influence treatment response and long-term outcomes.

But major disease drivers in people whose tumors have no evidence of  USP8 mutations are unknown. Recognizing this gap, researchers in China examined tumor tissue samples from 22 patients with pituitary ademonas but a normal USP8 gene.

Their analysis revealed four genes that were recurrently mutated, including two — BRAF and USP48 — never before reported in this disease setting. Then, looking at 91 samples from patients, researchers found BRAF mutations in 17% of cases and USP48 mutations in 23% of patients.

These mutations were also found in patients with USP8-mutant pituitary tumors, but at a much lower rate — 5.1% for BRAF and 1.2% for USP48 mutations.

However, mutations in these two genes were not seen in patients with pituitary tumors producing other hormones, suggesting they are “unique genetic signatures of [ACTH-producing] adenomas,” the researchers wrote.

The team also found that BRAF and USP48 mutations activate signaling pathways that lead to the production of proopiomelanocortin (POMC), which is the precursor of ACTH.

“ACTH overproduction is a hallmark of Cushing’s disease and appears to be frequently induced by mutations in genes that tightly regulate POMC gene transcription in the pathogenesis of this disease,” investigators wrote.

Patients with BRAF and USP48 mutations had significantly higher levels of midnight plasma ACTH and midnight serum cortisol, compared to patients without these mutations. Tumor size, however, was similar among the two groups.

Interestingly, the team found that the BRAF inhibitor Zelboraf (vemurafenib) effectively reduced ACTH production in cells from ACTH-producing pituitary tumors. Zelboraf, marketed by Genentech, is approved in the U.S. and Europe to treat cancers with BRAF mutations, and findings suggest it may be a good therapeutic candidate for some people with Cushing’s disease.

“The mutational status of BRAFUSP8, and USP48 in corticotroph adenomas may be used in the future to characterize the molecular subtypes and guide targeted molecular therapy,” the researchers suggested.

From https://cushingsdiseasenews.com/2018/11/20/mutations-in-usp48-braf-genes-contribute-for-cushings-disease-study-finds/

Rare Case of Cushing’s Disease Diagnosed in 7-year-old Boy

A recent case report describes a 7-year-old boy with Cushing’s disease who had an unusual clinical presentation, which significantly delayed his diagnosis.

The study, “A variable course of Cushing’s disease in a 7 year old: diagnostic dilemma,” was published in the Journal of Pediatric Endocrinology and Metabolism.

Rare in children and adolescents, Cushing’s disease refers to overproduction of cortisol caused by excessive adrenocorticotropic hormone (ACTH) secretion from a pituitary tumor. In pediatrics, early symptoms of excess cortisol include weight gain and delayed growth.

Despite being extremely unlikely in children younger than 7, some cases of Cushing’s disease in infancy have been reported.

“If undiagnosed or untreated it can lead to considerable morbidity and mortality, and the inability to detect a microadenoma [tumors smaller than 10 mm in diameter] on magnetic resonance imaging (MRI) can lead to a diagnostic dilemma leading to unnecessary delays in treatment initiation,” the researchers wrote.

Researchers from the Indraprastha Apollo Hospital in New Delhi, India, described a 7-year-old boy who complained of excessive appetite and weight gain in the previous five months. The child weighed 46.8 kg, was 127 cm tall, and had a body mass index (BMI) of 29, indicating he was overweight.

The child’s excess fat was mainly in his abdomen plus he had a round, red, puffy face, which are both common features of Cushing’s disease. He had no history of acute or chronic steroid intake, mood swings, sleep disorders, or issues with eyesight.

Given his clinical presentation, the investigators suspected the boy had Cushing’s disease or pseudo-Cushing’s disease, which refers to situations where the overproduction of cortisol is caused by something unrelated to the disease, such as stress or uncontrolled diabetes mellitus.

Biochemical testing showed the patient had high levels of cortisol, which remained unchanged after a dexamethasone suppression test. In addition, his levels of “bad” cholesterol, referring to low-density lipoprotein, were extremely elevated at 194 mg/dL, where a normal range is defined as less than 110 mg/dL.

Imaging revealed no lesions in the pituitary gland.

The boy was sent home with dietary recommendations. Eight weeks later, he had lost 4 kg, while his height remained the same; he also complained of headaches and various episodes of double vision.

This confused the clinical team as hallmarks of Cushing’s disease include short stature and weight loss triggered by pharmacological therapy. Despite having lost weight, he did not take any medications to help him with it, plus the boy’s height was normal for his age.

Nonetheless, the patient was complaining of neurological symptoms, suggesting progression of Cushing’s disease.

An ophthalmologist did not observe anything abnormal with the child’s eyes that could explain his double vision episodes.

A new series of tests revealed slightly elevated 24-hour urinary cortisol levels, decreased concentration of ACTH, and mildly increased cortisol levels after a two-day dexamethasone suppression test.

Magnetic resonance imaging (MRI) showed a small microadenoma in the right lobe of the pituitary gland.

Using Gamma Knife radiation therapy, a kind of high-precision radiation therapy, and surgery, doctors successfully removed the boy’s microadenoma. Six weeks post-procedure, his cortisol and ACTH concentrations returned to normal.

“MRI findings of the pituitary may be inconclusive in the beginning of the disease process and should be borne in mind during further follow-up. In cases where a clear-cut diagnosis may be difficult, a diligent follow-up is required to ascertain the course of the disease and to make timely diagnosis,” the investigators concluded.

From https://cushingsdiseasenews.com/2018/10/25/rare-case-cushings-disease-diagnosed-7-year-old-boy-case-study/

Rare Prostate Cancer Associated with Cushing’s Syndrome

A patient with depression developed Cushing’s syndrome (CS) because of a rare ACTH-secreting small cell cancer of the prostate, a case study reports.

The case report, “An unusual cause of depression in an older man: Cushing’s syndrome resulting from metastatic small cell cancer of the prostate,” was published in the “Lesson of the Month” section of Clinical Medicine.

Ectopic CS is a condition caused by an adrenocorticotropic hormone (ACTH)-secreting tumor outside the pituitary or adrenal glands. The excess ACTH then acts on the adrenal glands, causing them to produce too much cortisol.

Small cell cancer is more common in older men, those in their 60s or 70s. Sources of ectopic ACTH synthesis arising in the pelvis are rare; nonetheless, ACTH overproduction has been linked to tumors in the gonads and genitourinary organs, including the prostate.

Still, evidence suggests there are less than 30 published cases reporting ectopic CS caused by prostate cancer.

Researchers from the Southern Adelaide Local Health Network and the Royal Adelaide Hospital in Australia described the case of an 84-year-old man who complained of fatigue, back pain, and lack of appetite.

Blood tests revealed mildly elevated prostate-specific antigen (PSA) and creatinine levels, which could indicate the presence of prostate cancer and impaired kidney function, respectively.

The patient had a history of locally invasive prostate cancer even though he didn’t experience any symptoms of this disease.

Ultrasound examination showed an enlarged prostate plus obstructed ureters — the tubes that carry urine from the kidney to the bladder. To remove the obstruction, doctors inserted a thin tube into both ureters and restored urine flow.

After the procedure, the man had low levels of calcium, a depressed mood, and back pain, all of which compromised his recovery. Imaging of his back showed no obvious reason for his complaints, and he was discharged.

Eight days later, the patient went to the emergency room of a large public hospital because of back pain radiating to his left buttock. The man also had mild proximal weakness on both sides. He was thinner, and had low levels of calcium, high blood pressure and serum bicarbonate levels, plus elevated blood sugar. In addition, his depression was much worse.

A psychiatrist prescribed him an antidepressant called mirtazapine, and regular follow-up showed that his mood did improve with therapy.

A computed tomography (CT) scan revealed a 10.5 cm tumor on the prostate and metastasis on the lungs and liver. Further testing showed high serum cortisol and ACTH levels, consistent with a diagnosis of Cushing’s syndrome.

But researchers could not identify the ACTH source, and three weeks later, the patient died of a generalized bacterial infection, despite treatment with broad-spectrum antibiotics.

An autopsy revealed that the cancer had spread to the pelvic sidewalls and to one of the adrenal glands. Tissue analysis revealed that the patient had two types of cancer: acinar adenocarcinoma and small cell neuroendocrine carcinoma — which could explain the excess ACTH.

Cause of death was bronchopneumonia, a severe inflammation of the lungs, triggered by an invasive fungal infection.

Investigators believe there are things to be learned from this case, saying, “Neither the visceral metastases nor aggressive growth of the pelvic mass noted on imaging were typical of prostatic adenocarcinoma. [Plus], an incomplete diagnosis at death was the precipitant for a post-mortem examination. The autopsy findings were beneficial to the patient’s family and treating team. The case was discussed at a regular teaching meeting at a large tertiary hospital and, thus, was beneficial to a wide medical audience.”

Although a rare cause of ectopic ACTH synthesis, small cell prostate cancer should be considered in men presenting with Cushing’s syndrome, especially in those with a “mystery” source of ACTH overproduction.

“This case highlights the importance of multidisciplinary evaluation of clinical cases both [before and after death], and is a fine example of how autopsy findings can be used to benefit a wide audience,” the researchers concluded.

https://cushingsdiseasenews.com/2018/10/16/rare-prostate-cancer-prostate-associated-cushings-syndrome-case-report/

Minimally Invasive Approaches Lead to High Remission Rates in Children

Minimally invasive diagnostic methods and transnasal surgery may lead to remission in nearly all children with Cushing’s disease, while avoiding more aggressive approaches such as radiation or removal of the adrenal glands, a study shows.

The study, “A personal series of 100 children operated for Cushing’s disease (CD): optimizing minimally invasive diagnosis and transnasal surgery to achieve nearly 100% remission including reoperations,” was published in the Journal of Pediatric Endocrinology and Metabolism.

Normally, the pituitary produces adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands to produce cortisol. When a patient has a pituitary tumor, that indirectly leads to high levels of cortisol, leading to development of Cushing’s disease (CD).

In transnasal surgery (TNS), a surgeon goes through the nose using an endoscope to remove a pituitary tumor. The approach is the first-choice treatment for children with Cushing’s disease due to ACTH-secreting adenomas — or tumors — in the pituitary gland.

Micro-adenomas, defined as less than 4 mm, are more common in children and need surgical expertise for removal. It is necessary to determine the exact location of the tumor before conducting the surgery.

Additionally, many surgeons perform radiotherapy or bilateral adrenalectomy (removal of both adrenal glands) after the surgery. However, these options are not ideal as they can be detrimental to children who need to re-establish normal growth and development patterns.

Dieter K. Lüdecke, a surgeon from Germany’s University of Hamburg, has been able to achieve nearly 100% remission while minimizing the need for pituitary radiation or bilateral adrenalectomy. In this study, researchers looked at how these high remission rates can be achieved while minimizing radiotherapy or bilateral adrenalectomy.

Researchers analyzed 100 patients with pediatric CD who had been referred to Lüdecke for surgery from 1980-2009. Data was published in two separate series — series 1, which covers patients from 1980-1995, and series 2, which covers 1996-2009. All the surgeries employed direct TNS.

Diagnostic methods for CD have improved significantly over the past 30 years. Advanced endocrine diagnostic investigations, such as testing for levels of salivary cortisol in the late evening and cortisol-releasing hormone tests, have made a diagnosis of CD less invasive. This is particularly important for excluding children with obesity alone from children with obesity and CD. Methods to determine the precise location of micro-adenomas have also improved.

The initial methodology to localize tumors was known as inferior petrosal sinus sampling (IPSS), an invasive procedure in which ACTH levels are sampled from the veins that drain the pituitary gland.

In series 1, IPSS was performed in 24% of patients, among which 46% were found to have the wrong tumor location. Therefore, IPSS was deemed invasive, risky, and unreliable for this purpose.

All adenomas were removed with extensive pituitary exploration. Two patients in series 1 underwent early repeat surgery; all were successful.

Lüdecke introduced intraoperative cavernous sinus sampling (CSS), an improved way to predict location of adenomas. This was found to be very helpful in highly select cases and could also be done preoperatively for very small adenomas.

In series 2, CSS was used in only 15% of patients thanks to improved MRI and endocrinology tests. All patients who underwent CSS had correct localization of their tumors, indicating its superiority over IPSS.

In series 2, three patients underwent repeat TNS, which was successful. In these recurrences, TNS minimized the need for irradiation. The side effects of TNS were minimal. Recurrence rate in series 1 was 16% and 11% in series 2.

While Lüdecke’s patients achieved a remission rate of 98%, other studies show cure rates of 45-69%. Only 4% of patients in these two series received radiation therapy.

“Minimally invasive unilateral, microsurgical TNS is important functionally for both the nose and pituitary,” the researchers concluded. “Including early re-operations, a 98% remission rate could be achieved and the high risk of pituitary function loss with radiotherapy could be avoided.”

From https://cushingsdiseasenews.com/2018/09/04/minimally-invasive-methods-yield-high-remission-in-cushings-disease-children/