A series of vascular tumors and tumorlike lesions of the bladder.

Vascular tumors of the bladder are rare and a subject of small series and case reports. We retrospectively identified vascular tumors of the urinary bladder from the consultation files from one of the authors. We identified 13 lesions that included 3 hemangiomas, 3 intravascular papillary endothelial hyperplasias (Masson vegetant hemangioendotheliomas), 2 arteriovenous malformations (AVMs), 1 epithelioid hemangioendothelioma (EHE), and 4 angiosarcomas. One of the angiosarcomas was associated with conventional high-grade urothelial carcinoma (sarcomatoid carcinoma). All patients were adults with a range in age from 18 to 85 years old (mean 63.3). There was no statistical difference among the various lesions in terms of age, although angiosarcomas tended to arise in older patients (mean 71 y vs. 60 y of the remainder). Hematuria was the most common presentation of both benign and malignant lesions. Other symptoms included voiding irritation, pelvic pain, and obstruction. Histologically, benign and malignant lesions were similar to their counterparts in other organ systems. Two hemangiomas were of the capillary type and a third one of the cavernous subtype. They measured 1.1, 2.4, and 3.2 cm. Both AVMs were clinically large broad-based masses measuring 5.5 and 5.8 cm in greatest diameter. One of the AVMs was associated with pseudoepitheliomatous hyperplasia of the urothelium. All 3 patients with Masson lesion had history of radiation therapy for other causes. These presented as raised lesions and were all <1.0 cm. Patients with hemangiomas, papillary endothelial hyperplasias, and AVM had an invariably benign prognosis and needed no further therapy. These benign lesions had consistent involvement of the submucosa and spared the muscularis propria of the organ. All cases of angiosarcoma and EHE involved the muscularis propria. Two of four patients with angiosarcoma had a history of prior radiation therapy and all 4 were dead of disease at 6 months. Angiosarcomas measured 3, 4.5, 5, and 5.8 cm in greatest diameter at cystoscopy. The patient with EHE had a single nodule treated by transurethral resection of the bladder and no evidence of disease at 4 years of follow-up. None of the patients experienced marked gross hematuria that resulted in morbidity or mortality. A wide spectrum of benign, intermediate malignant, and malignant vascular lesions primarily involved the bladder. Despite the potential for marked hemorrhage, none of the tumors resulted in marked hematuria. Papillary endothelial hyperplasia occurs in the bladder and must be differentiated from angiosarcoma, which has a rapidly fatal outcome.