A 36-year-old man sought care after 1 week of right upper quadrant and epigastric abdominal pain. He reported that the pain was dull, constant, at times radiated to his back, and was worse postprandially. He denied nausea, vomiting, fever, or chills. On initial examination, he was afebrile with moderate tenderness in the right upper quadrant, with no guarding or rebound. A right upper quadrant mass was visible and palpable. His white blood cell count was 16.3 × 103μL and the results of liver function tests were normal. A computed tomographic scan of the abdomen showed a markedly thickened and heterogeneous enhancing gallbladder wall (Figure 1). A gallbladder ultrasound revealed a grossly abnormal gallbladder with a thickened and hyperemic wall.