BACKGROUND: Sarcomatoid renal cell carcinoma is not a distinct histologic entity transformed from different subtypes of renal cell carcinoma. The sarcomatoid transformation was accepted as the result of dedifferentiation of the primary tumor. Here we present a case of sarcomatoid chromophobe renal cell carcinoma and review the clinicopathological characteristics of sarcomatoid chromophobe renal cell carcinoma.

CASE REPORT: A 63-year-old female complained of painless gross hematuria for 3 months. Routine urine test showed that urinary protein was ++ and white blood cells were +++; serum CA153 was moderately elevated at 71.08 U/mL (normal <28 U/mL). Ultrasonography and a computed tomography scan showed a mass in the lower pole of the right kidney, measuring 13.4×15.4×11.4 cm. She underwent a right radical nephrectomy with lymph nodes dissection under general anesthetic. There was no evidence of recurrence and lymphadenopathy 12 months after surgery.

CONCLUSIONS: Sarcomatoid chromophobe renal cell carcinoma is an uncommon tumor characterized by a biphasic tumor with both classical epithelial components and sarcomatoid components. The prognosis of sarcomatoid chromophobe renal cell carcinoma is worse than classical chromophobe renal cell carcinoma. It is important to recognize that sarcomatoid change of chromophobe renal cell carcinoma has the potential to behave aggressively and to metastasize.

Keywords: Carcinoma, Renal Cell, Pathology, Clinical, Biomarkers, Tumor, Cell Dedifferentiation, Kidney Neoplasms, Leukocytosis, Lymph Node Excision, Nephrectomy, Proteinuria