AIDS-related lymphoma in Brazil: Histopathology, immunophenotype, and association with Epstein-Barr virus

Abstract

The occurrence of malignant lymphoma is an increasingly important cause of morbidity and mortality in AIDS patients. The incidence of AIDS-related lymphoma in some developing countries such as Brazil is increasing as the survival of HIV infection has improved. Although there is a clear association between several types of immunodeficiency-related lymphomas and Epstein-Barr virus (EBV), the association of EBV infection in AIDS-related lymphoma in Brazil, where the incidence of AIDS is high, is unknown. Formalin-fixed, paraffin-embedded tissue from 24 cases of AIDS-related lymphoma in Brazil were analyzed for morphologic classification, immunophenotype, and EBV association using in situ hybridization studies with an EBV-EBERI biotinylated probe. Twenty cases of AIDS-related lymphoma were classified as non-Hodgkin's lymphoma and four cases were Hodgkin's disease. Eleven non- Hodgkin's lymphomas were classified as diffuse large cell type, five cases were small non-cleaved cell, Burkitt-type, and four cases were large cell immunoblastic non-Hodgkin's lymphoma. Eighteen cases were of B-cell phenotype; one was a T-cell lymphoma, and one was classified as null. Epstein-Barr virus (EBV) was demonstrated in the majority of tumor cells of 11 of 20 (55%) of the cases non-Hodgkin's lymphomas and in 3 of 4 (75%) cases of Hodgkin's disease. AIDS-related lymphomas in Brazil are usually of large cell/immunoblastic type, but Hodgkin's disease is also seen. Both non- Hodgkin's lymphoma and Hodgkin's disease are often associated with EBV infection. The non-Hodgkin's lymphoma is predominantly of B-cell phenotype.

While there is a clear association between several types of immunodeficiency-related lymphomas and Epstein-Barr virus (EBV), the association of EBV infection in AIDS-related lymphoma in Brazil, where the incidence of AIDS is high, has remained unknown. The authors report their findings from an analysis of tissue samples from 24 cases of AIDS-related lymphoma in Brazil. The samples were analyzed for morphologic classification, immunophenotype, and EBV association. 20 cases were classified as non-Hodgkin's lymphoma, while 4 were Hodgkin's disease. 11 non-Hodgkin's lymphomas were classified as diffuse large cell type, 5 as small, non-cleaved cell, Burkitt-type, and 4 as large cell immunoblastic non-Hodgkin's lymphoma. 18 cases were of B-cell phenotype; one was a T-cell lymphoma and one was classified as null. EBV was demonstrated in the tumor cells of 11 of the 20 non-Hodgkin's lymphoma cases and in 3 of the 4 cases of non-Hodgkin's disease.