[Intravascular large B-cell lymphoma: report of two autopsy cases with literature review].

Objective: To study the clinicopathologic features of intravascular large B-cell lymphoma (IVLBCL).
Methods: Two autopsy cases of IVLBCL were retrieved from the archival file. The clinicopathologic features, immunohistochemistry and molecular findings were studied.
Results: The deceased were 70-year-old and 50-year-old males. Both of them had complained of a sudden onset of weakness and numbness of lower extremities. The clinical course deteriorated rapidly, with multi-organ failure. They died 85 days and 44 days after the presentation, respectively. Post-mortem examination did not reveal any mass lesion, except the presence of multiple skin and epicardium nodules, ranging from 0.5 cm to 2.5 cm in diameter, in the first patient. Pericardial effusion, ascites and pleural effusion were also observed. Histologically, neoplastic lymphoid cells filled up the small vessel lumina in many organs, including brain, hypophysis, spinal cord, spinal nerve roots, heart, lungs, kidneys, liver, spleen, digestive tract, pancreas, adrenal, thyroid, testes and lymph nodes. The tumor cells were relatively monotonous and of medium to large in size with round vesicular nuclei and 1 to 3 small basophilic nucleoli. Immunohistochemical study showed that the lymphoma cells expressed B-cell markers CD20 and CD79a, occasionally positive for CD5 and bcl-2 but negative for CD3, bcl-6, CD10, CD30, myeloperoxidase and cytokeratin. In-situ hybridization for Epstein-Barr virus-encoded RNA was negative. The proliferative index, as demonstrated by Ki-67 staining, was about 80%. Molecular study showed the presence of immunoglobulin heavy chain gene rearrangement in both cases, T-cell receptor-gamma gene rearrangement was not found.
Conclusions: IVLBCL may present as neurological disturbance and carries distinctive morphologic characteristics, immunophenotype and molecular findings. The prognosis of this disease is often dismal.