Squamous cell carcinomas and adenosquamous carcinomas originating from the thyroid gland

Three cases of squamous cell carcinoma and 3 cases of mixed squamous and glandular carcinoma were reported. Pathologic differential diagnosis of these rare primary tumors of the thyroid gland were discussed. All except 1 case occurred in elderly patients; their clinical behavior was more aggressive than that of differentiated papillary or follicular carcinoma of the thyroid gland and more like that of undifferentiated carcinoma. It is suggested that the tumor be treated more vigorously at its initial stage.