Adrenal cortical adenoma in a 13-year-old girl with neurofibromatosis. Case report and review of the literature

Double NF1 inactivation affects adrenocortical function in NF1Prx1 mice and a human patient

BACKGROUND

Neurofibromatosis type I (NF1, MIM#162200) is a relatively frequent genetic condition, which predisposes to tumor formation. Apart from tumors, individuals with NF1 often exhibit endocrine abnormalities such as precocious puberty (2,5-5% of NF1 patients) and some cases of hypertension (16% of NF1 patients). Several cases of adrenal cortex adenomas have been described in NF1 individuals supporting the notion that neurofibromin might play a role in adrenal cortex homeostasis. However, no experimental data were available to prove this hypothesis.

MATERIALS AND METHODS

We analysed Nf1Prx1 mice and one case of adrenal cortical hyperplasia in a NF1patient.

RESULTS

In Nf1Prx1 mice Nf1 is inactivated in the developing limbs, head mesenchyme as well as in the adrenal gland cortex, but not the adrenal medulla or brain. We show that adrenal gland size is increased in NF1Prx1 mice. Nf1Prx1 female mice showed corticosterone and aldosterone overproduction. Molecular analysis of Nf1 deficient adrenals revealed deregulation of multiple proteins, including steroidogenic acute regulatory protein (StAR), a vital mitochondrial factor promoting transfer of cholesterol into steroid making mitochondria. This was associated with a marked upregulation of MAPK pathway and a female specific increase of cAMP concentration in murine adrenal lysates. Complementarily, we characterized a patient with neurofibromatosis type I with macronodular adrenal hyperplasia with ACTH-independent cortisol overproduction. Comparison of normal control tissue- and adrenal hyperplasia- derived genomic DNA revealed loss of heterozygosity (LOH) of the wild type NF1 allele, showing that biallelic NF1 gene inactivation occurred in the hyperplastic adrenal gland.

CONCLUSIONS

Our data suggest that biallelic loss of Nf1 induces autonomous adrenal hyper-activity. We conclude that Nf1 is involved in the regulation of adrenal cortex function in mice and humans.

Neurofibromatosis type 1 associated with pheochromocytoma: a case report and a review of the literature

Pheochromocytoma (PHEO) occurs in 0.1-5.7% of patients with neurofibromatosis type 1 (NF1). We report a case of adrenal PHEO in a patient with NF1. A 30-yr-old Turkish man was admitted to our hospital for further examinations of a right adrenal mass, that was incidentally discovered by abdominal ultrasonography during examinations for acute hepatitis B infection in another hospital. In his past medical history, the patient had only had one palpitation, sweating and headache episode 4 yr before. On admission, his blood pressure was 110/70 mmHg. Physical examination revealed signs of NF1. He had multiple neurofibromas over the entire skin, café-au-lait spots on the trunk and extremities and skinfold freckling. Bilateral opthalmic examination revealed multiple Lisch nodules. The 24-h ambulatory blood pressure monitoring revealed paroximal hypertension attacks (190/148 mmHg). Urinary catecholamines were markedly increased. Magnetic resonance imaging (MRI) revealed a solid round tumor approximately 5 cm in diameter, located in right adrenal gland. A 131Iodine-metaiodobenzylguanidine (131I-MIBG) scan showed uptake in the right adrenal gland. The pre-operative treatment with an alpha-blocker (phenoxybenzamine) was performed. Right adrenalectomy was performed; the surgical specimen revealed PHEO. Urine catecholamines and their metabolites returned to normal ranges on post-operative day 7. In conclusion, an adrenal mass can be incidentally discovered in any patient. After diagnosis of NF1, patients who have episodes of hypertension, sweating, headache and palpitation should be evaluated for PHEO.

Pediatric adrenal cortical carcinoma: brain metastases and relationship to NF-1, case reports and review of the literature

Adrenal cortical carcinoma (ACC) is a rare childhood neoplasm that seldom manifests brain metastases; hence few papers in the literature focus on neurological manifestations associated with ACC. Although ACC is known to be a signature tumor type in several inherited cancer predisposition syndromes, particularly Li Fraumeni, ACC has not been previously associated with neurofibromatosis, type 1 (NF-1), an inherited disorder with frequent CNS lesions that might prompt concern for metastatic disease by neuroimaging studies. We present two pediatric patients with ACC and unusual CNS findings. The first child developed metastasis to the brain 4 years after resection of his adrenal primary and 2 and 1 years, respectively, after metastases to the liver and lungs. Soon after our experience with this patient, a girl with known NF-1 presented with virilization; adrenalectomy disclosed an ACC and systemic metastases were found within months. Disseminated disease prompted concern that her complex intracranial lesions identified by neuroimaging studies might represent brain metastases, but this proved to be NF1-related hamartomatous lesions. We review the literature on ACCs in pediatric patients regarding brain metastases and previous associations with NF-1.

von Recklinghausen's disease and pheochromocytomas

PURPOSE

We review the literature and characterize the clinical findings of von Recklinghausen's associated pheochromocytoma.

MATERIALS AND METHODS

A Grateful Med search for the years 1966 to 1999 was performed on the subjects, "von Recklinghausen" and "neurofibromatosis." Articles from the Grateful Med search were then reviewed to identify older publications. Of 325 articles 118 are included in this review.

RESULTS

Pheochromocytomas have been clinically identified in 0.1 to 5.7% of patients with von Recklinghausen's disease. Mean patient age was 42 years (range 1.5 to 74) in 87 women and 61 men at presentation with pheochromocytoma. Of the 148 patients 84% had solitary adrenal tumors, 9.6% bilateral adrenal disease and 6.1% ectopic pheochromocytomas. Symptoms related to pheochromocytoma or hypertension were noted in 78% of the patients. Tumors secreted epinephrine and norepinephrine, and 87% demonstrated metaiodobenzylguanidine uptake. Of the 148 patients 6% died during pregnancy or a medical procedure, or due to hypertensive crisis without apparent provocation, 8.8% had gastrointestinal carcinoid tumors and 11.5% had metastases or local invasion from pheochromocytoma.

CONCLUSIONS

Pheochromocytomas occur in a small but defined number of patients with von Recklinghausen's disease, and can be associated with significant morbidity and mortality if not detected. Screening of patients with von Recklinghausen's disease and hypertension or before provocative procedures or pregnancy seems to be indicated.

Multiple endocrine neoplasia: how many syndromes?

The phrase multiple endocrine neoplasia (MEN) generally denotes an association of tumors so specific as to constitute a syndrome. Three well-recognized such syndromes exist. All are autosomal dominant traits and all have been tentatively mapped to specific chromosomes. Other purported endocrine tumor syndromes have been suggested either as new entities or as subtypes of the existing MEN syndromes. The evidence in favor of these contentions is examined critically. Only one "new" association, that of pheochromocytomas and islet cell tumors, seems reasonable, and even in this setting, some relatives have had manifestations of von Hippel-Lindau syndrome. There is no compelling reason why such conditions as von Hippel-Lindau syndrome, peripheral neurofibromatosis, McCune-Albright syndrome, and others should be reclassified as MEN syndromes, although awareness of their collective endocrine abnormalities is clinically important.