Aspiration and imprint cytopathology of thyroid carcinoma associated with familial adenomatous polyposis.

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.