Abstract
We report a case of spindle cell type medullary carcinoma of the thyroid in a 77-year-old man. Fine needle aspiration cytology showed numerous spindle cells without inflammation and hemorrhage. The spindle cells were uniform and exhibited no malignant features. Immunocytochemistry was positive for carcinoembryonic antigen and calcitonin, and the tumor was diagnosed as spindle cell type medullary carcinoma. There are various histological subtypes of medullary carcinoma, and diagnosis by cytomorphology alone is difficult. Preservation with LBC fixative was helpful for diagnosis by immunocytochemistry in this case.
