Anatomical Pathology Interesting Case Conference

Discussion:

Bladder hemangioma is a very rare benign blood vessel and capillary tumor that represent only the 0.6% of all bladder tumors. The bladder is considered the second most common location of hemangiomas in the urinary tract, after the kidney (1). Most of them are solitary and sessile lesions, smaller than 3cm in diameter, that are usually found in the dome, trigone and posterior wall of the bladder. The majority of the hemangiomas extend into the bladder wall and are able to grow into the perivesical space, while approximately 30% of cases are limited only to the submucosa (2, 3). Hemangiomas of the urinary bladder have a male predominance and are usually diagnosed in patients under 30 years of age. Due to their congenital nature, they are usually present in the pediatric population. However, a study found an average age of presentation of 58 years-old (with a range between 19 and 76 years-old) (1,4).

Clinically, bladder hemangiomas can be asymptomatic (like our case report), however patients usually present with a painless gross hematuria that can range from few days to, even, 14 years (with a mean of 3.5 years). Marked anemia can be associated, as well as episodes of profuse bleeding. Other clinical symptoms can include lower abdominal pain and irritative voiding symptoms like vesical irritation and urinary retention (1, 5).

On ultrasound, bladder hemangiomas can appear as a circumscribed round intraluminal solid mass or can show a diffuse bladder wall thickening with punctate calcifications. MRI are superior to CT and ultrasound in assessing hemangiomas. It shows low to moderate signal intensity on T1 and a marked hypertense signal on T2. In cystoscopy, hemangiomas of the bladder usually present as sessile blue multilocular masses (1).

The histopathologic sections commonly show numerous proliferative capillaries with flattened endothelium lined with thin-walled, dilated, blood-filled vessels and plates that are sometimes thickened by adventitial fibrosis. The immunohistochemistry The immunohistochemistry shows a nuclear ERG expression in the epithelioid endothelial cells (1).