The importance of a tumor capsule in columnar cell thyroid carcinoma: a report of two cases and review of the literature.

Two cases of papillary columnar cell thyroid carcinoma are presented. A 49-year-old man presented with lymph node and pulmonary metastases at diagnosis; a 51-year-old woman developed local recurrence and lung and bone metastases 3 years postsurgery. Death occurred after 52 and 57 months, respectively. The first case lacked a tumor capsule, although the second exhibited capsule remains with extensive tumor cell infiltration. A review is made of all similar cases reported to date in the literature, placing emphasis on the epidemiological and prognostic differences observed in terms of circumscribed or noncircumscribed tumor. The presence of a capsule was associated with a higher frequency of female patients and a favorable prognosis. In contrast, tumors profusely infiltrating the thyroid parenchyma or extrathyroid tissues in the absence of a capsule, found in similar proportion of men and women had a fatal prognosis.