Case Report : A Calcitonin-Negative Neuroendocrine Tumor Derived from Follicular Lesions of the Thyroid

• Published in: Endocrinology and metabolism (Seoul) Vol. 30; no. 2; pp. 221 - 225
• Main Authors: Ga Young Kim, Chul Yun Park, Chang Ho Cho, June Sik Park, Eui Dal Jung, Eon Ju Jeon
• Format: Journal Article
• Language: Korean
• Published: 대한내분비학회 30-06-2015
• Subjects: Calcitonin; Carcinoma; medullary; Neuroendocrine tumors
• ISSN: 2093-596X

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.