Chromophobe Renal Cell Carcinoma and Xanthogranulomatous Pyelonephritisin the Same Kidney? A Case Report of a Rare Coexistence

Abstract

Introduction: ChRCC is an uncommon type of renal carcinoma classified into typical and the less met eosinophilic variant. The latter is likely to be mistaken for other renal eosinophilic tumors, needing an extended immunohistochemical investigation, in order to exclude other oncocytic renal tumors. XGP is an unusual benign condition which may mimic renal cell carcinoma grossly and microscopically, being a rare chronic inflammatory disorder forming masses in the renal parenchyma.In this report we present a rare case of coexisting ChRCC and XGP in the same kidney.

Case Presentation: A 51-year-old woman presented at the emergency unit with history of upper urinary tract infections, complaining about urinary frequency, and loin pain.  An abdominal CT scan revealed lesion near the renal pelvis of the left kidney and the patient underwent left nephrectomy  on a regular basis. The specimen we received included a brown and partially yellow tumor. The microscopical examination of the brown areas revealed sheets of small tumor cells with eosinophilic cytoplasm and wrinkled irregular nuclei. Microscopy of the yellow-colored areas revealed replacement of the renal parenchyma by an inflammatory infiltrate composed mainly foamy or pigmented –laden macrophages and rare giant cells, extending into the tumor-free renal parenchyma and the pelvic fat. These findings led us to the diagnosis of ChRCC with coexisting XGP.

Conclusions: Since both of these entities affecting the kidney are uncommon and they rarely coexist in the same kidney, the correct clinical and histological assessment is important forthe selection of proper treatment strategy