Pigmented renal cell carcinoma.
A rare case of pigmented renal cell carcinoma is presented. The tumor was yellow, somewhat elastic, and soft with focal gray and tan areas. Microscopically, the tumor was a typical renal cell carcinoma of the clear-cell type. Tumor cells containing brown pigment in the cytoplasm were scattered throughout the tumor. Ultrastructurally, the electron-dense granules consistent with the brown pigment noted at the microscopic level showed a coarse or fine granular matrix with or without homogeneous high electron-dense areas, resembling lipofuscin. However, the nature of the pigment was different from that of lipofuscin by the Masson-Fontana method after bleaching and rather similar to neuromelanin. The current case is a rare renal cell carcinoma with pigmentation attributed to abnormally excessive accumulation of neuromelanin pigment.
Kamishima
T
T
Second Department of Pathology, Niigata University School of Medicine, Japan.
Fukuda
T
T
Emura
I
I
Tanigawa
T
T
Naito
M
M
D000328:Adult; D002292:Carcinoma, Renal Cell / Q000737:chemistry / Q000473:pathology*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000737:chemistry / Q000473:pathology*; D008062:Lipofuscin / Q000032:analysis; D008543:Melanins / Q000032:analysis
D008062:Lipofuscin; D008543:Melanins; C014121:neuromelanin