Two unusual benign lesions of the neck masquerading as malignancy on fine-needle aspiration cytology.

Two cases of unusual benign tumors of the neck are described, both of which were initially misdiagnosed on cytology as carcinomas. Fine-needle aspiration findings in each case demonstrated a pleomorphic population of cells including bizarre multinucleated giant cells, the latter raising the false impression of malignancy. However, on review the cytological appearances of the tumors, a pleomorphic lipoma and a carotid body tumor, were characteristic. The correct diagnosis in each case would have been made or suggested if the pathologist had been familiar with the cytologic features characteristic of the lesion and the differential diagnosis of the head and neck tumors. In addition, the point is made that adequate clinical information is essential for the pathologist if all relevant conditions are not to be missed in the differential diagnosis.