[Malignant lymphomas of the liver: new diagnostic algorithms].

Primary hepatic lymphomas represent rare neoplasms, which are partly observed in association with chronic viral hepatitis, immunosuppression and autoimmune diseases. In contrast, secondary hepatic lymphomas are much more frequent and represent disseminated disease. Lymphomas involving the liver include, with decreasing frequency, diffuse large B-cell lymphoma, small lymphocytic lymphoma, Hodgkin's lymphoma, peripheral T-cell lymphoma, follicular lymphoma and extranodal marginal zone B-cell lymphoma. Many B-cell lymphomas in the liver reveal a characteristic infiltration pattern allowing a rapid and cost-effective diagnosis based on focused immunohistochemical analyses. In contrast, most T-cell lymphomas show a more diverse morphology, which is sometimes difficult to differentiate from a reactive condition. Therefore, additional molecular analyses are frequently necessary. The differential diagnosis includes hepatitis and inflammatory bile duct diseases, undifferentiated carcinoma, inflammatory myofibroblastic tumor as well as histiocytic and dendritic cell neoplasms.