A Case of Familial Medullary Thyroid Carcinoma with a E768D Mutation in RET Proto-Oncogene

Abstract

A medullary thyroid carcinoma, a neoplasm of parafollicular C cell origin, occurs as a sporadic or hereditary disease. A hereditary medullary thyroid carcinoma is an autosomal dominantly inherited disease, which is composed of multiple endocrine neoplasia 2A and 2B, with a familial medullary thyroid carcinoma. Germline mutations of the RET gene are the underlying cause of the majority of hereditary medullary carcinomas. Here, the case of a 42 years-old man with a familial medullary thyroid carcinoma, confirmed by the detection of a RET proto-oncogene mutation at exon 13 on codon 768 from a GAG(Glu) to a GAT(Asp), is described. The patient underwent a total thyroidectomy and modified radical neck dissection. His sister was found to have the same mutant gene.