Fine needle aspiration cytology of a granular cell tumor arising in the thyroid gland: a case report and review of literature.

Granular cell tumor (GCT) is an uncommon tumor of soft tissue, and rarely occurs in thyroid. In this article, we report the FNAC results and pathological analysis of a 14-year-old female who presented with a painless mass in the right lobe of thyroid gland. A resection of the right lobe and isthmus of thyroid were applied after cells with abundant strong eosinophilic cytoplasma, indistinct border and inconspicuous nucleolus were found in the FNAC of the mass. Postoperative pathology and immunohistology helped diagnosis the lesion as thyroid GCT. Differential diagnosis from five diseases and cell types were performed and a review of all eleven papers reporting thyroid GCT was provided.