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.