A case of fatal thoracic penetrating injury caused by Hokkaido sika deer antlers.

The deceased was a man in his 70s who was found near a hunting trap set up close to a farmland. A male Hokkaido sika deer was trap and appeared to have attacked the man. Autopsy findings included lacerations, skin abrasions, and subcutaneous muscle hemorrhage on the left side of the man's body. The deepest wound was a laceration on the upper anterior chest. Further examination revealed a dislocation of the right sternoclavicular joint, separation at the sternal attachment of the right first rib, laceration on the anterior surface of the ascending aorta, and surrounding mediastinal hematoma. Additionally, a laceration on the left cheek, with a circular blind-ended wound cavity extending to the left mandibular angle, was noted. The shape of these injuries corresponded to the tip of a Hokkaido sika deer's antlers. The cause of death was determined to be hemorrhagic shock due to aortic injury, attributed to a penetrating wound to the anterior chest caused by the Hokkaido sika deer's antlers. Few reports on deer-related injuries exist. International literature describes fatal deer attacks, often involving males during the breeding season. In Japan, encounters between wild deer and humans occur frequently. Therefore, this case report may help raise awareness of such injuries.