Pseudocarcinomatous epithelial hyperplasia in the bladder unassociated with prior irradiation or chemotherapy

Abstract

Pseudocarcinomatous epithelial hyperplasia in the bladder is a little known phenomenon, recognized to be associated with prior irradiation and/or chemotherapy. Whether this process can occur outside of this setting has not been studied. We identified 8 of these cases mimicking invasive urothelial carcinoma from our consultation files from 07/04 to 07/06 with no prior history of radiation or chemotherapy. The mean age at diagnosis was 65 years (range, 42 to 81 y), with 5 of the 8 males. Seven patients had a potential etiology for these changes that could either have resulted in localized ischemia or injury to the urothelium. These included case 1: atrial fibrillation, hypertension, congestive heart failure, gastrointestinal bleeding, and coronary artery vascular disease; case 2: coronary angioplasty, atrial fibrillation, hyperlipidemia, and amputation of arm for ischemia; case 3: hypertension, uncontrolled diabetes, hyperlipidemia, and atrial fibrillation; case 4: underlying arteriovenous malformation of the bladder; cases 5 to 6: history of indwelling Foley catheter; and case 7: history of radical prostatectomy for prostate cancer but no radiation. One patient had no potential contributing factors. All 8 patients presented with gross hematuria. At cystoscopy, 7 patients had polypoid lesions with 1 appearing nonpolypoid. Histologically, all cases showed epithelial proliferation of urothelium with cells having prominent eosinophilic cytoplasm. This process that mimicked invasive cancer within the lamina propria was marked in 3 cases (38%). Moderate nuclear pleomorphism was seen in 6 cases (75%). Only 1 case revealed mitotic figures. Ulceration was seen in 1 case. All cases showed some degree of hemorrhage with hemosiderin deposition identified in 3 cases (38%). Fibrin deposition was present in 1 case within the stroma, 3 cases in the vessels, and 4 cases in both. Five cases show stromal fibrosis. Edema and vascular congestion were common features (90% and 100%, respectively). Six out of 8 cases were accompanied by moderate to marked acute and chronic inflammation. The original diagnosis included nested variant urothelial carcinoma (1 case), atypical suspicious for invasive carcinoma (5 cases), hemangioma (1 case), and eosinophilic cystitis (1 case). Patients were followed for a mean of 16.5 months (range, 10 to 34 mo), and none developed bladder cancer. As a rare response to ischemia and chronic irritation, pseudocarcinomatous epithelial proliferations in the bladder may be confused with invasive urothelial carcinoma. Pathologists must be aware of the histologic changes mimicking cancer, and recognize that it can occur outside of the setting of prior irradiation or chemotherapy.