A 71-year-old man with a history of atrial fibrillation and hypertension presented to the emergency department with a one-day history of severe abdominal pain. Examination Vital signs are stable, laboratory findings reveal an expected INR of 2.8 but are otherwise unremarkable. A palpable tender mass can be felt in the right lower quadrant of his abdomen.

When the patient sits up, the location of his pain remains unchanged. A CT scan reveals the findings seen here.