Figure 1b. Stage 2 emphysematous cholecystitis. (a) Abdominal radiograph obtained in a 78-year-old diabetic man demonstrates gas within the gallbladder wall (arrows). (b) Photograph of the cut gross specimen shows areas of transmural infarction (arrows) and hemorrhagic necrosis (*). (c) Radiograph obtained in a different patient shows intramural gas that delineates the characteristic gallbladder shape (arrowheads). (d) Photomicrograph reveals diffuse edema, foci of hemorrhage (short arrows), and multiple cystic gas collections (long arrows) in the gallbladder wall.