Primary Non-Hodgkin's Lymphoma of the Gallbladder

Case Report A 40-year-old woman presented with back pain that was associated with pyelonephritis. It was resolved within a week using oral antibiotics, but abdominal sonography revealed gallbladder thickening and low-echoic masses near the gallbladder neck (Fig. 1A). Neither gallbladder stones nor bile duct dilatation was observed. Physical examination showed normal findings, and serum chemistry levels were within normal limits. CT showed gallbladder thickening and a soft-tissue density mass in the liver bed (Fig. 1B). Focal liver pathology and lymphadenopathy in the hepatoduodenal ligament were not observed. The gallbladder lesion showed low intensity on fat-suppressed T1-weighted MR images and high intensity on fat-suppressed T2-weighted images compared with those of the liver parenchyma (Figs. 1C and 1D). The intensity of the mass in the liver bed resembled that of the wall lesion. MR cholangiopancreatography (MRCP) showed no highintensity foci, which are usually seen on intramural diverticula in adenomyomatosis. Pathologic examination revealed a diffuse large B-cell lymphoma of the gallbladder with involvement of noncontiguous lymph nodes on the liver bed (Fig. 1E). Intraoperatively, lymphadenopathy was not identified in other sites. Biopsy at the iliac bone showed neither normocellular bone marrow nor tumor cells. Abnormal findings were not detected on PET with FDG or whole-body CT. After that operation, the patient was treated with chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone) for 6 months. She has remained free of disease for 7 months.