Spontaneous rectus sheath hematoma associated with warfarin administration: a case report.

Rectus sheath hematoma (RSH) can result from bleeding into the rectus abdominis muscle or a direct muscular tear; nontraumatic spontaneous RSH is a rare condition. Here, we report a case of spontaneous RSH associated with warfarin administration for the treatment of chronic thromboembolic pulmonary hypertension (CTEPH). An 87-year-old woman was referred to our hospital because of abdominal pain, nausea, and vomiting for 3 days. She was receiving warfarin for treating CTEPH. She had a bulging and hard lower abdomen with ecchymosis. Moreover, the bulging portion was highly tender, and a positive Carnett's sign was also observed. She reported no history of abdominal trauma. Abdominal computed tomography (CT) scan revealed right RSH. She was diagnosed with spontaneous RSH and admitted to our hospital. Warfarin was antagonized with an intravenous injection of vitamin K; hemostatic agents were intravenously administered. Gradually, her abdominal pain improved. She was finally discharged 12 days after the admission. Abdominal CT scan performed 17 days after the discharge revealed a reduction in the size of RSH. Despite not having a history of trauma, it is necessary to consider the possibility of RSH for patients receiving warfarin and complaining of abdominal pain.