Spontaneous rupture of hypogastric artery aneurysm into the bladder: a case report and review of the literature.

Isolated internal iliac artery (hypogastric) aneurysms are rare. The incidence is less than 0.9%. They are usually asymptomatic. Symptoms can be due to compression of adjacent pelvic structures such as the bladder, ureters, and colon. Rupture of hypogastric artery aneurysms into the bladder has rarely been reported and, when present, is associated with prior abdominal instrumentation or trauma. There is one case where an arteriovesicular fistula formed spontaneously without any instrumentation or trauma, similar to our case. We describe an unusual case of an 81-year-old male with spontaneous rupture of a hypogastric artery aneurysm into the urinary bladder presenting as gross hematuria. This case illustrates the importance of a high index of suspicion in diagnosis and early treatment to reduce morbidity and mortality.