Spontaneous Rectus Sheath Hematoma Presenting As Acute Abdomen in an Anticoagulated Patient: A Case Report.

Rectus sheath hematoma is an uncommon but important cause of acute abdominal pain that may closely mimic intra-abdominal surgical emergencies, resulting in diagnostic uncertainty and potential delays in management. We report the case of a 64-year-old woman receiving warfarin therapy for chronic atrial fibrillation who presented with sudden-onset severe lower abdominal pain associated with abdominal distension and signs suggestive of an acute abdomen. Clinical evaluation revealed localized abdominal wall tenderness, a palpable infraumbilical mass, anemia, and supratherapeutic anticoagulation. Contrast-enhanced computed tomography (CT) demonstrated a large left-sided rectus sheath hematoma extending below the arcuate line into the prevesical space, causing significant mass effect without evidence of active extravasation. The patient was managed successfully with conservative treatment, including discontinuation of anticoagulation, reversal of coagulopathy, blood transfusion, analgesia, and close hemodynamic monitoring, resulting in progressive clinical recovery and significant interval resolution on follow-up imaging. This case highlights the importance of considering rectus sheath hematoma in the differential diagnosis of acute abdomen, particularly in elderly anticoagulated patients or those with recent episodes of increased intra-abdominal pressure. Prompt recognition through careful clinical assessment and early cross-sectional imaging is essential to avoid unnecessary surgical intervention and to facilitate appropriate management.