title: Pigmented renal cell carcinoma.
abstract: 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.
authors.affiliation: Second Department of Pathology, Niigata University School of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kamishima
authors.forename: T
authors.initials: T
authors.lastname: Fukuda
authors.forename: I
authors.initials: I
authors.lastname: Emura
authors.forename: T
authors.initials: T
authors.lastname: Tanigawa
authors.forename: M
authors.initials: M
authors.lastname: Naito
mesh_terms: 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
chemical_list: D008062:Lipofuscin; D008543:Melanins; C014121:neuromelanin