Six members of a family with multiple endocrine neoplasia type 2A
Mira Siderova, Mila Boyadzhieva, Kiril Hristozov, Ljudmila Angelova, Ivan Krasnaliev, Krasimir Ivanov, Radoslav Radev & Rumen Nenkov
We report three generations of a family with MEN-2 A characterized by autosomal dominant inheritance and virtually 100% penetrance.
The proband, 35-year-old man, was diagnosed and operated for pheochromocytoma of the right adrenal gland and medullary thyroid carcinoma (MTC) with lymph node metastasis in 2009. His mother turned out to be operated for bilateral pheochromocytoma at the age of 47 (in 1994) and had had a thyroid nodule. She died at the age of 51 probably of metastatic disease. The oldest of her three sons, 42 years old brother of the proband, was asymptomatic with negative medical history. Laboratory data showed high plasma metanephrine, normetanephrine and calcitonin. CT revealed bilateral adrenal tumors, histologically verified as pheochromocytoma after surgery. Neck US examination detected thyroid nodules with FNAB of medullary carcinoma and cervical lymph node metastasis with the same cytology and he will be soon operated. The second brother, now 40 years old, had had thyroidectomy at the age of 28 because of MTC with lymph node metastasis. Our investigations showed high plasma levels of metanephrine and normetanephrine and CT detected bilateral masses, pheochromocytoma on histology after the operation.
The genetic examination of the three brothers revealed RET mutation at codon 634, responsible for the MTC with lymph node metastasis in all of them, as well as bilateral pheochromocytomas in two of the brothers and unilateral in the youngest. Their plasma parathormone was normal and US and CT did not discover any enlarged parathyroid glands.
Their asymptomatic children, a 16-year-old son of the second brother, and a 7-year-old daughter of the youngest brother, were also screened and turned out to be gene carriers of the same mutation. A total prophylactic thyroidectomy will be performed because of the high risk of developing aggressive MTC.