Liver involvement by lymphoma: identification of a distinctive pattern of infiltration related to T-cell/histiocyte-rich B-cell lymphoma.

Liver biopsy specimens from 62 patients with hepatic infiltration by miscellaneous lymphomas were retrospectively studied. The most relevant histologic features of liver infiltration in the various subtypes of lymphomas were then compared. In this study, diffuse large B-cell lymphomas were the most common neoplasm to involve the liver as primary or secondary tumors (64.5% of cases). The next most common lymphoma to involve the liver was Hodgkin's disease, found in 19.4% of cases, followed by peripheral T-cell lymphomas (9.7%), follicle center cell lymphomas (4.8%), and primary hepatic marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue type (1.6%). Within the group of large B-cell lymphomas, a particular subset of cases was found, which was identified as T-cell/histiocyte-rich B-cell lymphoma. This rare variant of diffuse large B-cell lymphomas involves the liver in a very distinctive way that may mimic, on both clinical and histologic grounds, inflammatory liver disease or hepatic infiltration by Hodgkin's disease. Although these diagnostic ambiguities can be easily solved by current immunohistochemistry, awareness of these potentially misleading features is mandatory to avoid misdiagnosis.