LAUSR

Medullary thyroid carcinoma (MTC) is an uncommon malignancy of C- cell origin that accounts for < 3% of all thyroid cancers. 1,2 However, the prognosis for MTC, which is derived from parafollicular C cells, has generally been worse than the prognosis for differentiated thyrocyte- derived carcinomas, and it thus accounts for a dispro-portionate number of deaths from thyroid carcinoma. The clinical course of MTC has been found to be largely stage- dependent. Ten- year survival for thyroid- confined MTC is ~ 90%– 100%, whereas for MTC with nodal and distant spread, 10- year survival is ~ 32% and ~ 17%, respectively. 3 It is well understood that earlier detection of MTC has led to improved outcomes and overall patient survival. 4– 8 Better imaging, biochemical testing, and advanced tissue- based diagnostic pathological protocols, all of which rely on sufficient access for patients to an equipped health care system, are all essential to this. As pathologists, though, we must have the tools to con-sistently make the best diagnosis when slides arrive at our desks. Fine- needle aspiration cytology (FNAC) has limited sensitivity for the diagnosis of MTC, and ancillary testing may be essential for improving our diagnostic accuracy. 9,10 Molecular tests increasingly are being used in the diagnosis of thyroid lesions, and their validation for MTC consequently serves as a significant point of interest. This is the focus of a recent article by Randolph et al. 11 published in Thyroid , which serves as the basis for this commentary.