[Thyroid-like follicular carcinoma of the kidney].

Thyroid-like follicular carcinoma of the kidney (TLFCK) is an extremely rare histological variant of renal cell carcinoma, not yet included in the WHO list of tumors. This tumor has a characteristic morphological structure strikingly resembling follicular carcinoma of the thyroid gland, but differing from itby the immunophenotype of tumor cells. TLFCK is characterized by an indolent clinical course, rarely metastases, and even the presence of metastases does not lead to a worsening of the prognosis for the patient. Described a case of TLFCK diagnosed in a 38-year-old patient, observed clinically for 8 years, without metastases during this time, and removed by focal kidney resection. The paper presents the macroscopic and microscopic characteristics of the tumor, immunohistochemical profile, and discusses the issues of differential diagnosis.