Stable remission after administration of rituximab in a patient with primary hepatic marginal zone B-cell lymphoma.

We describe a case of primary hepatic marginal zone B-cell lymphoma in a 36-year-old Caucasian male with a history of chronic hepatitis B infection. Immunohistochemically, extensive infiltration by a CD20-positive, CD5- negative and CD10-negative lymphoid cell population displaying a follicular arrangement was detected. Molecular analysis of immunoglobulin heavy chain gene rearrangements confirmed the clonal expansion of lymphoma cells. Fourteen months after surgical treatment, the tumour recurred in close proximity to the liver hilus, hampering further surgery. Therefore, we implemented a therapy using the monoclonal anti-CD20-antibody rituximab in a dose of 375 mg/m(2), administered four times once a week. Six, 10, 18, and 26 months later the recurrent lymphoma could no longer be detected as shown by abdominal ultrasonography and CT. This case report demonstrates the difficulties of treating this extremely rare liver disease and shows its response to rituximab therapy.