Follicular variant of thyroid papillary carcinoma: a clinicopathologic study of six cases.

The clinicopathologic features of six cases of a peculiar variant of differentiated carcinoma of the thyroid composed of follicles with or without solid areas and having a characteristics ground-glass appearance of the nuclei were studied and compared with those of conventional papillary and follicular carcinomas. This variant resembled papillary carcinoma in its biologic behavior and all morphologic features with the exception that papillae were not present. The term "papillary carcinoma, follicular variant" is proposed for this tumor type in order to emphasize its close biologic relationship with the conventional papillary carcinoma.