Pigmented Renal Cell Carcinoma: A Case with Unusual Findings and Review of the Literature

A few cases of pigmented renal cell carcinoma have been reported in the literature so far. It has been described in both conventional and chromophobe subtypes of renal cell carcinoma. The nature of these pigmentations is consistent with melanin, neuromelanin, and lipochrome granules. We report a rare case of pigmented renal carcinoma due to the accumulation of abnormal phagolysosomal bodies, with histochemical features consistent with neuromelanin. A review of cases of pigmented conventional renal cell carcinoma in literature is also presented. Awareness of pigmentation in primary renal cell carcinoma is important in differentiating it from primary and metastatic malignant melanoma and other malignancies that can show pigmentation. Whether the presence and nature of the pigmentation has any clinical importance has yet to be established.