A 52-year-old man presented to the emergency department with a history of acute left lower quadrant pain. On examination, he was normotensive and mildly tachycardic with a low-grade fever. He had a firm, distended abdomen with left lower quadrant tenderness. Computed tomography (CT) revealed diverticulitis and a large mass on the right side of the abdomen. This mass was further examined with magnetic resonance imaging (MRI) (Figure 1), which revealed that the mass displaced the kidney inferiorly, the liver superiorly, and the inferior vena cava and the second part of duodenum medially. After resolution of hisdiverticulitis, a laparotomy was performed through a midline incision. The mass (Figure 2) was removed without complication, and the patient made a speedy recovery with early discharge.