Endocrine Abstracts

The multiple endocrine neoplasia syndrome type 2A (MEN 2A) is the consequence of a heritable mutation in the RET proto-oncogene, leading to a very high predisposition to develop medullary thyroid carcinoma (MTC), pheochromocytoma and primary parathyroid hyperplasia. Screening of ‘at-risk’ family members and prophylactic thyroidectomy is recommended – but not always easily accomplished.

Our proband was diagnosed with MTC in 1977 (at age 21), had a subtotal thyroidectomy and was lost to follow up until 1998 when he was discovered to have a calcitonin of >1000 pg/ml, but no therapy was pursued. In 2000, while admitted for acute pancreatitis, a 3 cm left adrenal mass was discovered on CT; the patient reported being hypertensive since age 18 (TAs=160 mmHg), without the spells suggestive of pheochromocytoma, but had high urinary metanephrines (1200 μg/24 h). MEN2A was first considered after he underwent left adrenalectomy, and pathology confirmed pheochromocytoma. By then age 46, he brought his two sons to the endocrine clinic – aged 22 and 14 years. Genetic testing revealed a mutation in codon 634 of the RET proto-oncogene. Both boys had marginally elevated calcitonin levels, therefore thyroidectomy was recommended, but both refused and signed. The grandfather, 75 years old and known to be diabetic, hypertensive and with coronary artery disease, carried the RET mutation and was diagnosed with pheochromocytoma (bilateral adrenal masses of 40/17 and 42/26 mm) and MTC (calcitonin 1200 pg/ml), as an example of the natural history of the disease. However, all cases were reluctant to pursue surgery until pheochromocytoma triggered admission into the hospital. Current treatment (unfortunately delayed too long) according to guidelines in this family is now in progress.

Our case series suggests that although the biology of MEN2A is currently better understood, with clear clinical guidelines certified by costly investigations, the recommended therapy is not always easily followed, with non-compliance being probably multifactorial.