Primary Hepatic B-Cell Lymphomas

Abstract

The liver is an organ that could either be involved by systemic lymphomas or rarely as a primary site of lymphomas. Although secondary involvement of the liver by lymphomas is relatively common, primary hepatic lymphomas (PHL) represent only about 0.016% of all cases of non-Hodgkin lymphomas (NHL) and 0.4% of all primary extranodal non-Hodgkin lymphomas. Most of these cases are B-cell lymphomas. Primary hepatic T-cell lymphomas are extremely rare. There is no national consensus regarding the diagnostic criteria of PHL. In general, it is a lymphoma confined to the liver without evidence of involvement in the spleen, lymph nodes, other lymphoid tissue, or bone marrow at the time of presentation and within the next 6 months. The etiology and pathogenesis of primary hepatic B-cell lymphomas (PHBCLs) are unclear. Most patients with PHBCLs present with right upper quadrant abdominal pain or discomfort, have hepatomegaly on examination, and have elevated liver function tests. Radiologically, PHBCLs may present as a solitary lesion, multiple lesions, or less commonly diffuse infiltrate of the liver. The most common histological type of PHBCL is diffuse large B-cell lymphoma (DLBCL). The prognosis is variable, but patients with PHBCLs may have a more favorable outcome than patients with systemic B-cell lymphomas involving the liver, when treated with early combination chemotherapy.