Fine-needle aspiration (FNA) is commonly used to evaluate both primary thyroid lesions (PTLs) and secondary thyroid neoplasms (STNs). Although STNs are uncommon, metastases from various primary sites particularly the kidney, lung, and breast have been previously described. Giant cell tumor (GCT) is typically found in the metaphyseal-epiphyseal area of long bones that seldom involves thyroid. The typical cytological feature of GCT on FNA smears is highly cellular dual cell pattern consisting of mononuclear stromal cells and multinucleate osteoclast-like giant cells. By performing FNA of the left lobe of thyroid and clinico-radiological evaluation, we were able to diagnose a mass in a 40-year-old male patient as GCT based on cytological specimen. To the best of our knowledge, this is the first case that a GCT is identified in the thyroid gland by FNA initially.
Keywords: fine-needle aspiration cytology; giant cell tumor; secondary thyroid neoplasm.
© 2018 Wiley Periodicals, Inc.