Death resulting from a mesenteric hemorrhage due to acute myeloid leukemia: an autopsy case.

Acute leukemia causes hemorrhage in various sites throughout the body, such as the brain parenchyma, resulting in serious complications. Here, we present an autopsy case where the patient succumbed to a ruptured mesenteric hematoma caused by acute leukemia. A 58-year-old man, without a significant past medical history, was found dead at his workplace. An external examination showed subcutaneous hemorrhage on the left upper extremity. Macroscopic autopsy findings revealed a massive hemoperitoneum (1000mL) and extensive hematoma in the mesentery. Histopathological findings showed monotonous cell proliferation not only in the mesentery, but in many organs, such as the liver, spleen, and kidney; aggregates of the infiltrating cells were also observed in the microvessels of various organs. Immunohistochemical staining indicated that the infiltrating cells showed variable myeloperoxidase positivity, and the cells were strongly positive for CD68 (PG-M1). From the autopsy findings and the immunohistochemical staining, we concluded that the underlying cause of death was acute myeloid leukemia (M5). This case was not only a rare presentation of acute leukemia, but provides a lesson to forensic pathologists regarding noting underlying hematological disease, particularly when a case of massive hemorrhage of unknown etiology is encountered.