Another dissertation on poorly differentiated carcinomas: is it really necessary?

Descriptions of poorly differentiated thyroid carcinomas, tumors with outcomes midway between that associated with well-differentiated and anaplastic carcinomas, have been prominent in the literature of the recent past. The neoplasms are characterized by the finding of poorly differentiated areas within papillary and follicular carcinomas. The work of Sakamoto clearly separates a group of poorly differentiated carcinomas, based on outcomes, from well-differentiated and anaplastic forms by the identification of schirrous, solid, and trabecular areas within papillary and follicular carcinomas. However, the presence of similar areas within more "benign" forms of papillary and follicular carcinomas may obviate the easy identification of such neoplasms in daily practice. This article presents a refinement of Sakamoto's classification and although suffering from the same limitations, may be of some practical value.