Visceral artery aneurysmal lesion of the omentum – a rare cause of spontaneous fatal intra-abdominal hemorrhage

We report unexpected death of a 72-year-old man due to a hemoperitoneum (1.9 L of blood in the abdominal cavity). Postmortem examination revealed that the cause of the hemorrhage was an arterial aneurysmal lesion in the greater omentum. The lesion measured 4 × 4 × 6 cm with a generally smooth wall, but with a focal area of rupture within a hemorrhagic region measuring 1 × 2 cm. There was a substantial feeding artery. Histological examination revealed features in keeping with a pseudoaneurysm, but also with some features of a true aneurysm. There was no history of trauma and the rupture of the aneurysmal lesion that had caused the hematoperitoneum was considered to be spontaneous. Prior to his death the deceased had attended hospital for epigastric pain, which was attributed to dyspepsia, but otherwise he had not had symptoms prior to his death.