[Eosinophilic polypoid cystitis with flat carcinoma in situ of the overlying epithelium]

A case of eosinophilic polypoid cystitis with flat carcinoma in situ of the overlying epithelium is described. This is the first case with such an association encountered in our series comprised of 26 bladder surgical specimens and represents an incidence rate of 0.38%. The clinical case described herein is that of a 62-year-old male patient with a clinical picture of hematuria, frequency and urgency. Patient cystoscopic evaluation revealed a congestive and edematous mucosa at the level of the trigone and sessile polyps. Microscopic examination revealed flat urothelium with anisokaryosis, hyperchromatic nuclei, atypical mitosis, and loss of polarity; chorion with diffuse, dense inflammatory infiltrate comprised of eosinophils accounting for greater than 90% of the cell population, plasma cells, mastocytes, edema and vascular congestion. Epithelial erosion and capillary thrombosis were also observed. We discuss the etiology, clinical features and treatment reported elsewhere.