Multiple cutaneous neuromas and macular amyloidosis associated with medullary thyroid carcinoma

Abstract

Multiple cutaneous neuromas are rarely seen in dermatology practice. We report a case of multiple cutaneous neuromas, macular amyloidosis (MA), and medullary thyroid carcinoma (MTC) and discuss the interrelationship of the associated conditions. Multiple endocrine neoplasia 2 (MEN 2) is a hereditary syndrome that comprises MEN 2A, MEN 2B, and familial MTC. Germline mutations in the RET protooncogene is the underlying cause of the syndrome. MEN 2A and MEN 2B show some common endocrine manifestations including MTC and pheochromocytoma. There are reports of families with MA and MEN 2A. Multiple mucosal neuromas occur in 100% of patients with MEN 2B syndrome. Cutaneous neuromas are infrequently reported in MEN 2B syndrome. Our patient was a heterozygote carrier of GAG --> GAC mutation (Glu 768 Asp) in exon 13, codon 768 of the RET proto-oncogene. We speculate that our patient may represent an unusual presentation of MEN 2B or an overlap of MEN 2A and MEN 2B syndromes or a sporadic MTC case with unusual associations.