Diffuse Follicular Variant of Papillary Thyroid Carcinoma: A Case Report with a Revision of Literature.

The diffuse follicular variant of papillary thyroid carcinoma (DFV-PTC) is a rare malignant thyroid condition. It represents an uncommon variant of papillary carcinoma characterized by a diffuse involvement of thyroid parenchyma, follicular architecture and nuclear features of PTC in absence of a surrounding capsule. Up to date few data have been collected about this entity and, at the best of our knowledge, only 24 cases have been reported in the literature. According to these reports DFV-PTC seems to occur preferentially in young women and shows more aggressive behavior than other papillary thyroid tumors. Herein we present an unusual case of DFV-PTC occurring in an 83 years old woman, involving the entire thyroid gland, without distinct or prevalent thyroid nodules. The tumor was clinically misdiagnosed as obstructive goiter.