Columnar cell carcinoma of the thyroid: report of three additional cases.

Columnar cell carcinoma is a recently described variant of thyroid carcinoma that has been associated with an aggressive clinical course. The authors describe three new cases of columnar cell carcinoma occurring in two women and one man aged 62, 46, and 46 years, respectively. The tumors ranged in size from 1 to 7.5 cm, and two of the tumors were associated with distant metastases. One patient died of disease 39 months after presentation. Another patient is alive with distant metastases 27 months after diagnosis. One patient appears to be a long-term survivor with no evidence of metastasis after follow-up of 22 years. This patient had a tumor that was small (1 cm) and encapsulated. DNA ploidy analysis in two tumors showed diploid DNA content, and there was no elevated S phase. All tumors were positive for thyroglobulin and negative for calcitonin and carcinoembryonic antigen (CEA). These findings support the original observation that columnar cell variants of papillary thyroid carcinoma are usually aggressive neoplasms. There does not appear to be an increased incidence of DNA aneuploidy in columnar cell carcinomas to account for their more aggressive behavior. These tumors occur over a wide age range, can metastasize widely, and are not usually responsive to radioactive iodine or chemotherapy.