Elucidating the etiology of idiopathic spontaneous intraperitoneal hemorrhage.

Free blood within the abdominal cavity (hemoperitoneum) presents a significant diagnostic and interpretive challenge. It may result from trauma or occur spontaneously in association with underlying disease conditions. When no source of fatal hemorrhage is identified, the implications extend across forensic, criminalistic, legal, and ethical domains. Idiopathic spontaneous intraperitoneal hemorrhage (ISIH), historically known as abdominal apoplexy, is characterized by fatal hemoperitoneum in the absence of trauma or known nontraumatic causes of intraabdominal bleeding. Rupture of a small intraabdominal vessel is suspected; however, the bleeding source usually remains unidentified. We report the case of a 45-year-old female with cirrhosis who succumbed to ISIH. Autopsy revealed massive hemoperitoneum and signs of exsanguination. Careful dissection of the abdominal cavity identified hemorrhagic ectopic venous varices beneath the right diaphragmatic arch, covered by an organized blood clot. Histological analysis confirmed recent hemorrhage and demonstrated suspected rupture of the parietal peritoneum near dilated ectopic venous varices. This case is evaluated in the context of pathophysiology, etiological theories, diagnostic limitations, potential contributions of imaging modalities, and forensic relevance. To our knowledge, this is the first reported case of ISIH with dual confirmation-both gross and histological-of hemorrhage originating from ectopic varices. These findings testify that rupture of ectopic venous varices may cause fatal hemorrhage in patients with cirrhosis and underscore the necessity of meticulous autopsy and histopathological correlation.