Pigmented microcystic chromophobe renal cell carcinoma in a patient with end-stage kidney disease: Importance of evaluating non-neoplastic renal parenchyma.

Adenomatous pigmented microcystic chromophobe renal cell carcinoma (PMCRCC) is a rare variant of chromophobe renal cell carcinoma. We report a 72-year-old male with end-stage chronic kidney disease undergoing transplant evaluation, in whom PMCRCC and concomitant focal segmental glomerulosclerosis (FSGS) were identified after nephrectomy. The tumor showed characteristic microcystic architecture, focal pigmentation, and immunophenotypic features. To our knowledge, this is among the few reported cases of PMCRCC with detailed evaluation of the accompanying non-neoplastic renal parenchyma. The case highlights the characteristic features of this rare tumor variant and illustrates the value of systematic assessment of non-neoplastic kidney tissue in nephrectomy specimens.