Large B-cell lymphoma with an unusual infiltrating pattern: report of two cases.

Large B-cell lymphoma presents with the most varied infiltrating patterns and morphologies. Here we report two cases of unusual large B-cell lymphoma in two old female patients. Both lymphomas show: 1) scattered and clustered large B-cells infiltrating the periphery of polyclonal lymphoid nodules; 2) large B-cells with an immunoblastic morphology; 3) large B-cell infiltration associated with vascular proliferation; 4) coexisting lymphoid nodules with hyaline vascular proliferation. The first case took an aggressive clinical course with transformation into acute leukemia, and imparted a short patient survival, whereas the second case responded to chemotherapy, experienced a local recurrence and long survival for >7 years. To our knowledge, these are the first reported cases of large B-cell lymphomas with a paranodular infiltrating pattern, immunoblastic morphology, and associated vascular proliferation.