Follicular, papillary, and "hybrid" carcinomas of the thyroid

Abstract

The existence of well-differentiated thyroid tumors sharing the clinicopathologic features of follicular and papillary carcinoma is discussed using the so-called diffuse (multinodular) form of the follicular variant of papillary carcinoma as a paradigm. Although the concept of a hybrid carcinoma of the thyroid is intellectually very appealing, we conclude that there is not (yet) enough reliable genotypic or phenotypic evidence to support utilization of such a term.