[Bleeding into retroperitoneal cavernous lymphangioma following blunt abdominal trauma].

The case of a 12-year-old boy with hemorrhage into a previously unknown retroperitoneal lesion following blunt abdominal trauma is reported. Diagnostic work-up of a post-traumatic surgical acute abdomen revealed a giant multicystic tumor in the retroperitoneum, which could be completely removed. Histological examination confirmed the suspected diagnosis of congenital lymphangioma. Attention should be drawn to the possible coincidence of trauma and a preexisting asymptomatic lesion. Knowledge of the characteristic ultrasonographic and computer tomographic features is essential in order to make a correct diagnosis.