title: Solitary fibrous tumor of the kidney originating from the renal capsule and fed by the renal capsular artery.
abstract: Solitary fibrous tumors (SFT) are relatively rare spindle cell neoplasms that typically arise in the pleura. Recently, extrathoracic SFT that have arisen in various anatomic sites have been recognized. The histogenesis and prognosis of SFT of the kidney are not well understood because only 11 cases have been reported. We report a case of SFT of the left kidney arising from the renal capsule. The tumor was merged with the upper pole of the left renal capsule. The angiography revealed that the renal capsule artery fed the tumor. The tumor was a well-circumscribed, solid mass attached to the renal capsule without necrosis or hemorrhage. Microscopically the bland spindle cells proliferated and were accompanied by hyalinized collagenous tissue showing patternless or hemangiopericytomatous patterns. Some glomeluri and renal tubules were entrapped by the tumor cells. There were no mitotic figures. Immunohistochemically the tumor cells were diffusely positive for CD34, CD99 and bcl-2. There was no evidence of recurrence after a 4 year follow-up visit. The origin of SFT of the kidney remains uncertain. The tumor in this case merged with the renal capsule and was fed by the renal capsular artery, which suggests that some SFT of the kidney originate from the renal capsule.
authors.affiliation: Department of Urology, Nagoya Daini Red Cross Hospital, 2-9 Myoken-cho Showa-ku, Nagoya 466-8650, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamada
authors.forename: Toyonori
authors.initials: T
authors.lastname: Tsuzuki
authors.forename: Keisuke
authors.initials: K
authors.lastname: Yokoi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kobayashi
mesh_terms: D000071443:12E7 Antigen; D000792:Angiography; D015703:Antigens, CD / Q000378:metabolism; D018952:Antigens, CD34 / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D018218:Neoplasms, Fibrous Tissue / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism
chemical_list: D000071443:12E7 Antigen; D015703:Antigens, CD; D018952:Antigens, CD34; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; D019253:Proto-Oncogene Proteins c-bcl-2