Occult thyroid cancer discovered by fine-needle aspiration cytology of cervical lymph node: a report of three cases.

Three cases of occult thyroid cancer measuring 10, 6, and 3 mm in diameter were discovered by fine-needle aspiration cytology of cervical lymph nodes. In these three cases, thyroid tumors were not palpable, and scintigraphic, echographic, and soft-tissue radiologic examinations demonstrated no abnormalities of the thyroid glands. Cytologically, the presence of intranuclear cytoplasmic inclusions, nuclear grooves, and colloid was characteristic in aspirated materials. Histologically, all three cases were diagnosed as papillary carcinoma. Fine-needle aspiration cytology of cervical lymph node was very useful to find occult carcinoma of the thyroid gland.