[Epidermoid carcinoma of the kidney]

Epidermoid carcinoma of the kidney is a rare malignant tumor, characterized by high invasiveness, poor prognosis, and the association of renal stone and renal infection. Very little reports about its sonographic appearance were mentioned in the literature. We present a case of epidermoid carcinoma of the kidney. Its ultrasonography showed a heterogeneous renal mass with perirenal and pararenal invasion, destruction of the renal pelvis, and preservation of enlarged reniform outline. Although this tumor should be differentiated with renal cell carcinoma, transitional cell carcinoma, renal metastatic tumor, renal lymphoma, renal infarction, focal bacterial nephritis, and xanthogranulomatous pyelonephritis etc., we think we should put epidermoid carcinoma of kidney into consideration when a renal tumor mass presents with perirenal and pararenal invasion, destruction of the renal pelvis, and preservation of enlarged reniform outline in sonography, and hypovascularity in angiographic study.