Endocrinology and Metabolism  2015;30(2):221-225

doi:10.3803/EnM.2015.30.2.221

A Calcitonin-Negative Neuroendocrine Tumor Derived from Follicular Lesions of the Thyroid.

Ga Young KIM 1 ; Chul Yun PARK ; Chang Ho CHO ; June Sik PARK ; Eui Dal JUNG ; Eon Ju JEON

Affiliations

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Keywords

Calcitonin; Carcinoma, medullary; Neuroendocrine tumors

Country

Republic of Korea

Language

English

Abstract

Neuroendocrine lesions of the thyroid are rare. The most common types are medullary thyroid carcinomas (MTCs) and C-cell hyperplasia. MTCs originate from thyroid parafollicular cells that secrete calcitonin which serves as a serum marker of MTCs. Here, the rare case of a calcitonin-negative neuroendocrine tumor (NET) derived from follicular lesions of the thyroid is described. A 34-year-old man presented at our hospital for the surgical management of an incidental thyroid nodule that was observed on an ultrasound sonography (USG) of the neck. Initially, USG-guided aspiration cytology was performed, and a MTC was suspected. The expressions of thyroglobulin and thyroid transcription factor-1, which are thyroid follicular cell markers, and synaptophysin and chromogranin A, which are neuroendocrine markers, was confirmed following surgical pathology. However, the staining of calcitonin, a marker of MTCs, was not observed. A nonmedullary NET of the thyroid is uncommon, and the distinction between calcitonin-negative NETs and MTCs of the thyroid may be important due to differences in their clinical courses and management.