Urothelial carcinoma with rhabdoid features: report of 6 cases.

Extrarenal rhabdoid tumors have been described in a variety of primary sites with only rare case reports of urothelial carcinomas with rhabdoid features in the literature. In this report, we describe the clinicopathologic characteristics, including clinical follow-up on 6 cases of urothelial carcinoma with prominent rhabdoid features. Four cases were retrieved from the consultation files of one of the authors and 2 were retrieved from the surgical pathology files at our institution. The patients were all men, with ages ranging from 53 to 86 years (mean, 66.5 years). Patients initially presented with hematuria or obstructive symptoms. The sites included bladder (n = 4) and renal pelvis (n = 2). All cases had a prominent rhabdoid component (mean, 60%), ranging from 40% to 80%. In addition to the rhabdoid component, multiple coexistent histological components were seen, including in situ urothelial carcinoma (carcinoma in situ) and high-grade papillary urothelial carcinoma (n = 2), poorly differentiated carcinoma with small-cell features (n = 1), sarcomatoid (n = 2), and a myxoid component (n = 2). All cases in this series had focal or diffuse positive staining with one or more cytokeratin markers (epithelial membrane antigen, CAM 5.2, AE1/AE3). Of the 6 patients, 4 were treated initially with surgery (radical cystoprostatectomy, n = 2; radical nephrectomy, n = 2). Of 6 patients, 2 died within 1 month, whereas a third patient died within 4 months. The remaining 3 patients were alive at 3, 3, and 9 months after diagnosis. The histological and immunohistochemical findings in this study serve to broaden the morphological spectrum of urothelial carcinomas with prominent rhabdoid features and add further evidence as to their poor prognosis.