title: A synchronous occurrence of urothelial carcinoma with abundant myxoid stroma and inverted papilloma of the urinary bladder.
abstract: Abundant myxoid stroma rarely occurs in urothelial carcinomas, and may cause diagnostic challenges when cells with eosinophilic cytoplasm forming nests and cords in a myxoid background are seen, particularly in the absence of typical carcinomatous appearance. Microscopic examination of transurethral resection specimen of a 71-year-old male patient revealed non-cohesive oval or elongated tumor cells with eosinophilic cytoplasm arranged in cord-like filigree pattern in an abundant myxoid stroma. Immunohistochemically the tumor was positive for cytokeratin 7, cytokeratin 20, and 34BE12. About 90 to 100% nuclear staining was observed with p63, p53, and Ki-67. A second neoplasm with a flat overlying urothelial epithelium and a complete inverted cellular growth pattern was also noted. The neoplasm exhibited less than 2% and 10% nuclear staining with Ki-67 and p53, respectively. Considering histological, histochemical, and immunohistochemical findings, a diagnosis of synchronous urothelial carcinoma with abundant myxoid stroma and inverted papilloma was made.
authors.affiliation: Department of Pathology, Istanbul Education and Research Hospital, Ministry of Health, Istanbul;
authors.forename: Kemal
authors.initials: K
authors.lastname: Behzatoğlu
authors.forename: Pelin
authors.initials: P
authors.lastname: Yildiz
authors.forename: Meltem
authors.initials: M
authors.lastname: Oznur
authors.forename: Erol R
authors.initials: ER
authors.lastname: Bozkurt
keywords: inverted papilloma.; myxoid; transitional cell carcinoma; urinary bladder; urothelial carcinoma