Expression of immunohistochemical markers in patients with AIDS-related lymphoma.

AIDS-related lymphomas (ARL) present high biological heterogeneity. For better characterization of this type of lymphoma, the objectives of the present study were to evaluate the expression of immunohistochemical markers of cell differentiation (CD10, Bcl-6, MUM-1) and determine cell origin profile according to Hans' classification of diffuse large B-cell lymphoma in AIDS patients. This study included 72 consecutive patients with ARL diagnosed at the University Hospital, Universidade Federal do Rio de Janeiro (UFRJ) and at the Brazilian Instituto Nacional de Câncer (INCA) from 2000 to 2006. The morphologic distribution of the lymphomas was the following: 61% were diffuse large B-cell lymphomas (DLBCLs), 15% were Burkitt's lymphomas, 13% were plasmablastic lymphomas, 10% were high-grade lymphomas and 1% was follicular lymphoma. The positivity for each immunohistochemical marker in DLBCLs, Burkitt's lymphoma and plasmablastic lymphoma was respectively: CD20, 84%, 100%, and 0; CD10, 55%, 100%, and 0; Bcl-6, 45%, 80%, and 0; MUM-1, 41%, 20%, and 88%. A higher positivity of CD20 (84% x 56%, p = 0.01) was found in DLBCL compared to non-DLBCL; in Burkitt's lymphomas a higher positivity of CD10 (100% x 49%, p = 0.04) and Bcl-6 (80% x 39%, p = 0.035) were found compared to non-Burkitt's lymphomas. Germinal center (GC) profile was detected in 60% of DLBCLs. Our study suggests particular findings in ARL, as the most frequent phenotype was GC, different from HIV-negative patients.

Expression of immunohistochemical markers in patients with AIDS-related lymphoma

AIDS-related lymphomas (ARL) present high biological heterogeneity. For better characterization of this type of lymphoma, the objectives of the present study were to evaluate the expression of immunohistochemical markers of cell differentiation (CD10, Bcl-6, MUM-1) and determine cell origin profile according to Hans' classification of diffuse large B-cell lymphoma in AIDS patients. This study included 72 consecutive patients with ARL diagnosed at the University Hospital, Universidade Federal do Rio de Janeiro (UFRJ) and at the Brazilian Instituto Nacional de Câncer (INCA) from 2000 to 2006. The morphologic distribution of the lymphomas was the following: 61 percent were diffuse large B-cell lymphomas (DLBCLs), 15 percent were Burkitt's lymphomas, 13 percent were plasmablastic lymphomas, 10 percent were high-grade lymphomas and 1 percent was follicular lymphoma. The positivity for each immunohistochemical marker in DLBCLs, Burkitt's lymphoma and plasmablastic lymphoma was respectively: CD20, 84 percent, 100 percent, and 0; CD10, 55 percent, 100 percent, and 0; Bcl-6, 45 percent, 80 percent, and 0; MUM-1, 41 percent, 20 percent, and 88 percent. A higher positivity of CD20 (84 percent x 56 percent, p = 0.01) was found in DLBCL compared to non-DLBCL; in Burkitt's lymphomas a higher positivity of CD10 (100 percent x 49 percent, p = 0.04) and Bcl-6 (80 percent x 39 percent, p = 0.035) were found compared to non-Burkitt's lymphomas. Germinal center (GC) profile was detected in 60 percent of DLBCLs. Our study suggests particular findings in ARL, as the most frequent phenotype was GC, different from HIV-negative patients.

Unusual case of plasmablastic non-Hodgkin's lymphoma located in the liver. First case reported in an AIDS patient.

Plasmablastic lymphoma is a rare and a relatively new entity that was first described in the jaws and the oral cavity of HIV-AIDS patients. We report a case of plasmablastic lymphoma involving the liver in an AIDS patient. Plasmablastic lymphoma is considered a diffuse large B-cell lymphoma with a unique phenotype and predilection for the oral cavity. The case presented had a unique hepatic lesion, localized in the left lobe of the liver. Diagnosis was confirmed by hepatic biopsy guided by Computerized Tomography scan and histopathology. The smears showed a dense infiltrate composed by atypical lymphocytes with numerous plasmocytes expressing the plasma cell markers MUM-1 and CD138 and negative for the B-cell markers CD3, CD20 and CD45. Immunohistochemical and in situ hybridization revealed the Epstein-Barr virus genome in the atypical cells. Polymerase chain reaction was negative for HHV-8 RNA.