Thyroid carcinomas occur in association with familial adenomatous polyposis (FAP), and some are the first symptom of FAP. Although several histological features have been reported, the cytopathology of FAP-associated thyroid carcinoma has not yet been described. We report on two cases of FAP-associated thyroid carcinomas diagnosed by fine-needle aspiration biopsy and one case imprinted after resection. All 3 patients belonged to the same family, and thyroid carcinoma was the first symptom of the proband. Cytological features include fascicular or whorl formation of spindle cells with papillary, follicular, and/or solid architectures, in addition to the typical features of papillary carcinoma. The cytological features of FAP-associated thyroid carcinomas are characteristic and may suggest FAP.
Copyright 2000 Wiley-Liss, Inc.