[Clinicopathologic characteristics of primary thyroid-like follicular carcinoma in kidney].

Objective To explore the clinicopathological characteristics of primary thyroid-like follicular carcinoma of the kidney.Methods A case of primary thyroid-like follicular carcinoma of the kidney was studied with histology and immunohistochemical staining,and its clinical and pathological findings were further analyzed with review of the literature.Results The patient was a 26-year-old asymptomatic woman who had a kidney mass during her annual physical examination.The tumor was well-circumscribed.Pathologically,the tumor showed follicular structures with colloid-like material in the lumina.Immunohistochemically,the tumor cells showed intense staining for CK7 and vimentin and negative for thyoid transcripation factor-1,thyroglobulin,thyoid peroxidase and RCC.Conclusions The diagnosis of primary thyroid-like follicular carcinoma of the kidney is based on the characteristic follicular architecture with colloid-like material,and the metastasis from a thyroid follicular carcinoma must be excluded clinically and pathologically before making the final diagnosis. Key words: Kidney neoplasms ;  Immunohistochemistry;  Diagnosis, differential