Primary Hepatic Lymphoma: A Large Mass Surrounding Multiple Intrahepatic Vessels

Abstract

A man was hospitalized for a 7-day history of right upper-quadrant abdominal pain. Physical examinaion revealed mild hepatomegaly. Laboratory results showed a emoglobin level of 94 g/L, a platelet count of 66 109 g/L, a actate dehydrogenase level of 554 U/L, an alkaline phosphatase evel of 118 U/L, and a -glutamyl transpeptidase level of 65 U/L. Tumor markers were negative. Abdominal computed tomography (CT) with contrast revealed a 15.0 10.0 8.4 cm3 nonenhancing mass involving the right and left lobes of the liver on portal phase imaging (Figure A). Magnetic resonance imaging showed low signal on T1-weighted and high signal on T2-weighted fat-saturated sequences (Figure B). The mass showed mild rim enhancement on portal phase postcontrast T1-weighted sequence and surrounded the inferior vena cava, hepatic middle and right vein, and right portal vein without any deformity (Figure C). There was no mediastinal lymphadenopathy on chest radiography and no evidence of lymphoma on bone marrow biopsy. Liver biopsy showed diffuse lymphocytic infiltrate (Figure D). Immunohistochemical stains were positive for CD20 (Figure E), CD79a, and Ki-67 ( 40%), and negative for CD45RO. The diagnosis of diffuse B-cell lymphoma was made. After 6 cycles of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone, CT showed a dramatic reduction in the size of the tumor (Figure F). The patient was followed up for 2 years without recurrence or the need for additional therapy. This case highlighted several important points. A large mass surrounding multiple intrahepatic blood vessels without any architectural distortion was the characteristic of this tumor, which was to some extent similar to the sandwich sign for mesenteric lymphoma and the CT angiogram sign or floating aorta sign for retroperitoneal lymphoma. This finding is helpful in differentiating primary hepatic lymphoma (PHL) from most benign or malignant hepatic tumors that usually displace or invade the adjacent intrahepatic vessels. Lymphoma in general tends to surround adjacent vessels without compressing their lumen.1 Furthermore, although rare,2 it is important to rec-