title: Rare presentation of carcinosarcoma arising in bladder diverticulum.
abstract: An 87-year-old man presented with hematuria and dysuria. An endoscopic examination revealed a bladder mucosa which was almost entirely occupied by diverticula. On the left lateral wall of the bladder there was a huge diverticulum which contained a 12 cm mass extending beyond the bladder wall in the extraperitoneal tissues. Upon histological examination the mass proved to be a carcinosarcoma which was composed by a squamous carcinoma and a sarcoma resembling a malignant fibrous histiocytoma. The two components, i.e. carcinomatous and sarcomatous, were separated by a sharp collision border and no intermingling was ever noted. The epithelial component showed immunoreactivity for cytokeratin and EMA, while the mesenchymal component was diffusely reactive for vimentin, alpha-1-antitrypsin and lysozime. Both components were reactive for galectin-3, whereas S100, desmin and smooth muscle actin were negative. This is the fourth reported case of carcinosarcoma originating in a bladder diverticulum.
authors.affiliation: Dept. of Pathology, Catholic University of Sacred Heart, Rome, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Bigotti
authors.forename: A
authors.initials: A
authors.lastname: Coli
authors.forename: L A
authors.initials: LA
authors.lastname: Prisco
authors.forename: C
authors.initials: C
authors.lastname: Spina
authors.forename: F
authors.initials: F
authors.lastname: Russo
authors.forename: F
authors.initials: F
authors.lastname: Castri
authors.forename: G
authors.initials: G
authors.lastname: Massi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D002296:Carcinosarcoma / Q000737:chemistry / Q000175:diagnosis*; D004240:Diverticulum / Q000175:diagnosis*; D006801:Humans; D008297:Male; D009363:Neoplasm Proteins / Q000032:analysis; D001749:Urinary Bladder Neoplasms / Q000737:chemistry / Q000175:diagnosis*
chemical_list: D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins