Thyroid-Like Follicular Carcinoma of the Kidney With Low-Grade Sarcomatoid Component: A Hitherto Undescribed Case.

Thyroid-like follicular carcinoma of the kidney (TLFCK) is a rare subtype of renal cell carcinoma, which closely resembles follicular neoplasms of the thyroid and has a distinctive indolent clinical behavior. Until now, a single case of TLFCK with extensive sarcomatoid differentiation has been documented with aggressive clinical course. We present an unusual case of sarcomatoid TLFCK with a low-grade spindle cell component in a 34-year-old male patient, with an indolent course following radical nephrectomy and regional node dissection.