Abstract

Intravascular papillary endothelial hyperplasia (IPEH) is an uncommon benign vascular disease characterized by endothelial cell proliferation and papillary formation within the lumen of blood vessels arising from an organizing thrombus. The occurrence of this uncommon lesion is about 2 of all vascular tumors. IPEH mostly occurs in the 5th decade of life, and there is no gender or age predilection. Nevertheless, some studies have suggested that IPEH is more common in women than in men. The clinical features are mostly asymptomatic, and the lesion is typically characterized as a small, firm, slightly elevated mass with red to blue discoloration of the overlying skin. The main diagnosis of the lesion is based on histological examination. The most common locations of IPEH are head and neck, fingers, and trunk. The occurrence of IPEH in the urethra is extremely rare, with only a few cases having been reported in the literature. We describe a 70-year-old woman with a complaint of dysuria and urethral bleeding of 3 days' duration. Clinically, the lesion was a palpable firm mass in the urethra. Urethrocystoscopy illustrated a dark mass, a few millimeters in size, with bleeding. Histologic findings revealed dilated blood vessels with multiple papillary projections into the lumen. Thus, based on these findings, a final diagnosis of Masson's tumor was confirmed. According to clinical and radiographic findings, this lesion is similar to malignant lesions and its accurate diagnosis is based on microscopic findings. Therefore, awareness of the microscopic characteristics of this tumor is very important for clinicians to rule out the presence of malignant vascular lesions and to avoid unnecessarily aggressive therapy.