Clinical characteristics and pathology of thyroid-like follicular carcinoma of the kidney: Report of 3 cases and a literature review.

Thyroid-like follicular carcinoma (TLFC) of the kidney is an extremely rare type of renal tumor, which has not been classified under a known subtype of renal cell carcinoma. It is histologically similar to the primary thyroid follicular carcinoma; however, the characteristics lack thyroid immunohistochemical markers. The aim of the present study was to illustrate the clinical characteristics of 3 new cases along with a review of the literature. The patients were compared with regards to gender, age, location and size of the tumor, imageology, morphology, immunohistochemistry and prognosis. According to the limited data, TLFC occurs mainly in young women and its clinical manifestations have no difference with other renal tumors. Its imageological features resemble a large spectrum of benign and malignant renal and extra-renal conditions, which should be eliminated in the diagnostic process. Confirmed diagnosis depends on the examination of pathology and immunohistochemistry. Surgical ablation is the preferred therapeutic method. Currently, TLFC has a relatively good prognosis; however, this conclusion requires further cases and long-term follow-ups. Improving the understanding of TLFC can help avoid misdiagnosis and prevent inappropriate treatment.