Fine-needle aspiration diagnosis of ectopic thyroid: report of one case.

Fine-needle aspiration (FNA) of a mass of the floor of the mouth in a teenage woman showed many foamy and pigmented histiocytes, cholesterol crystals, and few sheets of follicular cells with paravacuolar granules and cytoplasmic flares. The cytologic findings were consistent with adenomatous thyroid tissue. This was confirmed by subsequent surgical excision and histologic diagnosis of the surgical specimen. The differential diagnosis and value of preoperative diagnosis by FNA of lesions of the floor of the mouth in general and ectopic thyroid in particular, are briefly discussed.