Renal Squamous Cell Carcinoma Presenting With Renohepatic Fistula: A Rare Amalgam

Background: Primary squamous cell carcinoma (SCC) of the kidney, a rare malignancy that accounts for less than 1% of all urinary tract malignancies, is usually diagnosed in late stages because of the lack of characteristic clinical and imaging features and aggressive behavior. Case Report: A 66-year-old male presented with complaints of right flank pain. Imaging suggested the differential diagnoses of xanthogranulomatous pyelonephritis or renal malignancy extending into segment VI of the liver. Right subcapsular nephrectomy was performed, and nonbilious fluid from the liver cavitary lesions was drained. Histopathologic examination showed that the lesion was a renal SCC with contiguous malignant infiltration of the liver that led to a renohepatic fistula. Conclusion: Renal SCC is a rare high-grade neoplasm and can present in an unusual form with a poor prognosis.