Parathyroid adenoma and bilateral pheochromocytoma in a patient with neurofibromatosis

[Pheochromocytoma associated with primary hyperparathyroidism and type 1 neurofibromatosis]

Neurofibromatosis type 1 (NF-1) is a predominantly inherited genetic disease with prevalence of 1 per 2500-3000 newborns and based on clear clinical criteria. In addition to common neurofibromas and gliomas of the visual pathways, these patients have a higher risk of various benign and malignant tumors throughout their lives including tumors of the central nervous system, membranes of peripheral nerves, gastrointestinal stromal tumors and leukemia. Endocrine diseases and neoplasms also occur in patients with NF-1 and can include extrarenal paraganglioma, primary hyperparathyroidism, gastroenteropancreatic neuroendocrine tumors, thyroid tumors and other adrenal neoplasms. We demonstrate multiple neuroendocrine neoplasia (MEN 2A) of neurofibromatosis type 1 combined with pheochromocytoma and primary hyperparathyroidism in a woman with a long history of palpitations, paroxysmal hypertension and osteoporosis. Biochemical analysis revealed severe hypercalcemia with elevated parathyroid hormone indicating primary hyperparathyroidism, as well as high fractionated normetanephrine and metanephrine in the urine as a sign of catecholamine-releasing pheochromocytoma/paraganglioma. Further scintigraphy revealed signs of solitary parathyroid adenoma causing primary hyperparathyroidism and right-sided pheochromocytoma. Clinical diagnosis of MEN-2 syndrome is based on combination of at least two major MEN-2-associated endocrine tumors. Resection of parathyroid adenoma and pheochromocytoma normalized biochemical parameters and blood pressure. Combination of pheochromocytoma with primary hyperparathyroidism and type 1 neurofibromatosis is discussed.

Prevalence of Associated Endocrine Diseases in Patients with Neurofibromatosis Type 1

Background  Neurofibromatosis type 1 (NF-1) is an autosomal dominant neurocutaneous disorder that increases the risk of developing benign and malignant tumors. Several associated endocrine diseases in NF-1 patients have been explained in the literature. Thus, this study aims to assess the endocrine manifestations as there no previous local data have discussed this association.

Methods  A retrospective cross-sectional study was conducted at KAMC and KASCH, Riyadh, Saudi Arabia by including all patients genetically confirmed with NF1 from 2004 until 2019 using a consecutive non-probability sampling technique. The included data were demographics, consanguinity, genetic variant mutations as well as associated endocrine diseases.

Results  The prevalence of patients with associated endocrine diseases was estimated to be 19.4%. Short stature showed the highest frequency of associated endocrine diseases followed by subclinical hypothyroidism. Positive consanguinity, sporadic mutation, and pathogenic variant showed high frequencies.

Conclusion  The coexistence of endocrine diseases was found in NF-1 patients. Therefore, screening for endocrine abnormality in patients with NF-1 by comprehensive history and physical exam as well as investigations to minimize complications and the late presentation should be considered; however, further studies are necessary to address the need.

Parathyroid Carcinoma Causing Mild Hyperparathyroidism in Neurofibromatosis Type 1: A Case Report and Systematic Review

BACKGROUND

Neurofibromatosis type 1 is an autosomal dominant disorder characterized by an increased incidence of tumors, including endocrine ones. Primary hyperparathyroidism can be rarely caused by a parathyroid carcinoma; these patients are generally characterized by severe symptoms, large neck lesions and high levels of PTH and calcium. We report a case of hyperparathyroidism due to parathyroid carcinoma in a patient affected by neurofibromatosis type 1. A systematic review of the literature was also conducted.

PATIENT FINDINGS

A 56-year-old woman was referred for a 13 mm-nodular lesion of the neck incidentally discovered on ultrasound examination and mild hyperparathyroidism. A 99mTctetrofosmin/ pertechnetate subtraction scintigraphy was negative for parathyroid disease. Given the absence of suspicious ultrasound finding, a fine-needle aspiration cytology was performed with iPTH determination in the aspirate, confirming the parathyroid origin of the lesion. The patient underwent left inferior parathyroidectomy with intraoperative monitoring of iPTH and became normocalcemic. On histopathological examination, parathyroid carcinoma presenting at the resection margin was diagnosed, thus a surgery revision was requested.

CONCLUSION

Even if literature does not support a syndromic association between neurofibromatosis type 1 and primary hyperparathyroidism, the benefit of precociously diagnosing and treating this condition may outweigh costs associated with screening. This case report moreover demonstrates that sometimes clinical, laboratory and imaging aspects suspicious for cancer may be missing. A prompt referral to a high-volume center is crucial for the management of those cases of incidental histopathological diagnosis.

Concurrent primary hyperparathyroidism and pheochromocytoma in a Chinese lady with neurofibromatosis type 1

We report a case of elderly Chinese lady with neurofibromatosis type-1 presenting with longstanding palpitation, paroxysmal hypertension and osteoporosis. Biochemical testing showed mild hypercalcaemia with non-suppressed parathyroid hormone level suggestive of primary hyperparathyroidism, and mildly elevated urinary fractionated normetanephrine and plasma-free normetanephrine pointing to a catecholamine-secreting pheochromocytoma/paraganglioma. Further scintigraphic investigation revealed evidence of a solitary parathyroid adenoma causing primary hyperparathyroidism and a left pheochromocytoma. Resection of the parathyroid adenoma and pheochromocytoma resulted in normalization of biochemical abnormalities and hypertension. The rare concurrence of primary hyperparathyroidism and pheochromocytoma in neurofibromatosis type-1 is discussed.

Learning points

All NF-1 patients who have symptoms suggestive of a pheochromocytoma/paraganglioma (PPGL), even remotely, should undergo biochemical testing.The initial biochemical tests of choice for PPGL in NF-1 are either plasma-free metanephrines or urinary fractionated metanephrines. Any elevations of metanephrines should be carefully evaluated for the presence of PPGLs in NF-1 patients.Primary hyperparathyroidism (PHPT) is described in subjects with NF-1. Due to the lack of epidemiological and functional studies, their association is yet to be substantiated. Meanwhile, PHPT may further exacerbate the metabolic bone defect in these patients and should be treated when present according to published guidelines.Coexistence of PPGL and PHPT can occur in subjects with NF-1, mimicking multiple endocrine neoplasia type 2 (MEN2).

Neurofibromatosis type 1, pheochromocytoma with primary hyperparathyroidism: A rare association

Primary hyperparathyroidism (PHP) with pheochromocytoma and neurofibromatosis type 1 is a rare clinical association. We present a case of PHP and pheochromocytoma occurring in a 33-year-old male with familial cutaneous neurofibromatosis.

Neurofibromatosis type 1: should we screen for other genetic syndromes? A case report of co-existence with multiple endocrine neoplasia 2A

BACKGROUND

NF 1 is a genetic disorder with an autosomal dominant pattern of inheritence. It is associated with neoplastic disorders mainly derived from the neural seath. However, the co-existence of NF1 with the full spectrum of MEN 2A has rarely been reported. The aim of the study was to investigate the presence of secondary neoplasias in a patient with diagnosed NF1, and in particular the presence of hyperparathyroidism and the possible co-existence with another pheochromocytoma-related syndrome.

METHODS

We report a case of a 70 years old female patient who had NF1. The patient was referred to our center and was diagnosed with an isolated pheochromocytoma of the right adrenal gland for which she underwent right adrenalectomy. We further investigated for the presence of another pheochromocytoma-related syndrome and in particular for the presence of hyperparathyroidism and medullary thyroid cancer. Molecular screening for germline mutations of the genes NF1, RET and VHL has also been performed.

RESULTS

The patient was further diagnosed with hyperparathyroidism and medullary thyroid cancer, having the full spectrum of the clinical picture of the MEN2A syndrome. The genetic testing revealed the germline mutation for NF1 but not for the RET proto-oncogene which is generally found in MEN2A cases.

CONCLUSION

To our knowledge this is a rare case of co-existence of two pheochromocytoma-related genetic syndromes, and generates the question of whether all patients with these syndromes should undergo a thorough clinical and laboratory investigation for the possibility of another co-existing pheochromocytoma-related genetic syndrome.

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.