Columnar cell carcinoma of the thyroid gland: a case report and review of the literature.

A rare case of columnar cell carcinoma of the thyroid gland is reported. The tumor was characterized by a predominantly papillary proliferation of tall columnar cells with marked nuclear stratification with associated focal areas showing solid or microfollicular growth. The nuclei of the tumor cells did not have the ground-glass appearance that characterizes papillary thyroid carcinoma; rather their nuclear features resembled follicular carcinoma. The tumor was found in an advanced stage and the patient died of lung metastases 2.5 years after surgery. The unique histopathological features and highly aggressive nature of columnar cell carcinoma require that this variant be differentiated from common papillary carcinoma of the thyroid. We also reviewed the literature emphasizing the lethal biological nature of this variant.