The columnar cell variant of papillary thyroid carcinoma is an aggressive tumor associated with wide spread dissemination and a fatal outcome. We report two cases of columnar cell carcinoma occurring in two women aged 27, 66 years, respectively. The histologic feature of both cases showed focal papillary growth with columnar cell and nuclear stratification. Recognizing the columnar cell variant of the thyroid is important in light of the aggressive nature of the lesion and its apparent resistance to standard therapeutic interventions. These tumors occur over a wide age range, can metastasize widely, and are not usually responsive to radioactive iodine or chemotherapy. The presence or absence of extrathyroidal invasion represents the single most important parameter in predicting the behavior of these tumors. A large series of these tumors is needed to more fully appreciate the clinicopathologic spectrum of this aggressive thyroid neoplasm.