HIVRelated Lymphomas

The incidence of non-Hodgkin lymphomas (NHL) in HIVpositive individuals is estimated to be between 4% and 10%, but the incidence of at least some subsets appears to be decreasing with combination antiretroviral therapy. The incidence of Hodgkin lymphoma is somewhat increased in HIV-infected individuals but is not considered to be an AIDS-defining condition. The pathogenesis of NHL in the context of AIDS is complex and thought to be related to disrupted immune surveillance, chronic antigenic stimulation, genetic alterations, cytokine dysregulation, and herpes virus infection.3-5

Although HIV-related lymphomas are almost always of B-cell origin, they are morphologically diverse. Several subtypes are similar to lymphomas occurring in immuno-competent patients, while others preferentially develop in the context of AIDS. HIV-related lymphomas can be classified by morphology (as in the WHO classification), primary site of presentation (i.e., systemic, primary central

Table 34-1. Common Features of Lymphoproliferations of

Immunodeficiency

Typically extranodal

Diffuse aggressive histology

B cell lineage

Rapid clinical progression

Often related to Epstein-Barr virus

Hypermutation of immunoglobulin genes and regulatory region of protooncogenes

Table 34-3. Correlation of Morphology and Viral Infection in HIV-Related Lymphomas

Virus

BL

CB

IB

PEL

Poly

PCNSL

EBV

25-75%

20-40%

80%

87%

40%

100%

LMP1+

0%

Rare

65%

Rare

ND

90%

KSHV

0%

0%

15%

100%

ND

0%

HIV-1

0%

0%

0%

0%

0%

0%

BL, Burkitt and Burkitt-like lymphoma;CB, centroblastic diffuse large B-cell lymphoma;IB, immunoblastic diffuse large B-cell lym-phoma;PEL, primary effusion lymphoma;Poly, polymorphic B-cell lymphoma (PTLD-like); PCNSL, primary CNS lymphoma; ND, not determined.

BL, Burkitt and Burkitt-like lymphoma;CB, centroblastic diffuse large B-cell lymphoma;IB, immunoblastic diffuse large B-cell lym-phoma;PEL, primary effusion lymphoma;Poly, polymorphic B-cell lymphoma (PTLD-like); PCNSL, primary CNS lymphoma; ND, not determined.

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