HIV infection significantly increases the risk for the development of lymphoma. NHL is present in about 3% of the HIV-positive people at the time of their diagnosis of HIV. Twenty percent of HIV-positive patients develop NHL.[1
] Risk factors for the development of NHL in HIV include a low CD4 T-cell count, high HIV viral load, increased age and male gender.[2
] In the study described by Agarwal et al., of 35 cases, seven cases were of Hodgkin disease, four of plasmacytoma and 24 cases were of NHL (three Burkitt’s lymphoma, four diffuse large B-cell lymphoma of centroblastic type, 10 immunoblastic type, four high-grade B-cell lymphoma [unspecified] and the remaining were other subtypes).[3
] In our patients, three different varieties of lymphoma were found, namely NHL (plasmablastic variety), Hodgkin’s lymphoma, nodular sclerosis type-II and B cell lymphoma, respectively. The diagnosis of AIDS precedes the onset of NHL in approximately 57% of the patients, but in 30%, the diagnosis of AIDS is made at the time of the diagnosis of NHL and HIV positivity.[4
] All our patients were diagnosed to be HIV infected prior to their diagnosis of lymphoma and all were already having AIDS at the time of presentation.
Plasmablastic lymphoma, originally described in 1997 in a series of 16 patients,[5
] is highly associated with advanced stages, and accounts for 2.6% of all HIV-related NHL. It is found with Ebstein barr virus (EBV) (15%) and Human Herpes virus 8 (HHV8) (38%) infection. Average age of onset is 33 years, much younger than would be expected for HIV-negative individuals, and commonly involves jaws, oral cavity, stomach, anorectum, nasal-paranasal areas and lungs.[6
] Our patient presented with cutaneous lesions, which appears to be rare. The tumors are characterized by immunoblastic morphology and plasma cell phenotype. Markers are positive mainly for LCA, CD79a, VS38C and CD138. In the pre-HAART era, prognosis of plasmablastic lymphoma was poor, with a median survival of about 5.5 months, although prognosis may have improved since the advent of HAART.
HIV-associated Hodgkin lymphoma, although not included in the CDC definition of AIDS, has been linked to HIV infection, with a relative risk of 11.5 in one study and predominance of two unfavorable subtypes: lymphocyte depleted and mixed cellularity.[8
] HIV-associated Hodgkin’s lymphoma presents in an aggressive fashion, often with extranodal or bone marrow involvement.[9
] A distinctive feature of HIV-associated Hodgkin’s lymphoma is the lower frequency of mediastinal adenopathy compared with non-HIV-associated Hodgkin’s lymphoma. In our case, the patient had extensive mediastinal adenopathy, which responded well with treatment.
AIDS-related lymphomas behave differently in the clinical setting and should be suspected in any patient with HIV who has a sudden increase in size of the lymphnode or presents with central nervous system (CNS) manifestations. Major differences from non-HIV patients are that these tumors have more aggressive clinical course, widespread involvement, are less responsive to chemotherapy and frequent relapse is seen. Chemotherapy consists of a much-reduced course of the standard chemotherapy regimens, half the dose of each component drug and for only four, rather than the usual 10, monthly treatments.[11
] Because chemotherapeutic agents are immunosuppressants, treatment of the malignancy increases the risk of opportunistic infections, thereby requiring prophylaxis. HAART appears to be a major positive prognostic factor for patients with AIDS.[12
] Among ART, Zidovudine is relatively contraindicated because of its marrow-suppressive effect. Protease inhibitors, mainly ritonavir, have the most significant effect on the cytochrome p450 system and hence increase the toxicities of chemotherapy agents. In the HIV-infected child in our series, the child was already on ART for 4 months. Most of the patients who have developed malignancy are the ones who were not on ART.
Prognosis of patients with AIDS-related lymphoma has been associated with extent of disease, extranodal involvement and bone marrow involvement, CD4 lymphocyte count, performance status and prior AIDS diagnosis. Median survival time ranges from 8 to 20 months, which is much poorer than the survival expected in patients with non-HIV-associated Hodgkin’s lymphoma.