Lymphomas associated with HIV

Epidemiology

The incidence of lymphoma in HIV-positive patients is increased by 60 to 200 times. These are mainly non-Hodgkin lymphoma, predominantly B-cell lymphomas, often of aggressive types; Hodgkin disease is increased eightfold. Lymphoma is the first AIDS-defining illness in 3-5% of patients. Herpes viruses, EBV and Kaposi Sarcoma Herpes Virus are thought to be causal. There is a marked propensity to involve extranodal sites.

Histopathology

• Burkitt lymphoma: 30% of HIV-associated lymphomas

• Burkitt lymphoma with plasmacytoid differentiation: 20% of HIV-associated lymphomas. It is almost unique to AIDS patients. EBV is positive in 50-70% of cases.

• Atypical Burkitt/Burkitt-like lymphoma. There is greater pleomorphism and more prominent nucleoli are seen. EBV is present in 30-50% of cases.

• Diffuse large B-cell lymphoma: 25% of HIV-associated lymphomas. They are usually of centroblastic type. EBV is present in 30% of cases. Cases showing immunoblastic differentiation are positive for EBV in more than 90% of cases. Some immunoblastic lymphoas in HIV-positive patients are associated with KSHV infection and represent a solid variant of PEL, never developing an effusion. Most lymphomas of the CNS in association with AIDS are of immunoblastic type.

• Hodgkin lymphoma. They are usually of mixed cellularity of lymphocyte depleted subtype. Most express LMP-1 and EBER.

• Primary effusion lymphoma.

• Plasmablastic lymphoma of the oral cavity. The tumour cells are large with eccentrically located nuclei and a single large central nucleolus. The cytoplasm is highly basophilic with a paranuclear hof. CD20 expression is lost. EBV is present in >50% of cases. The association with HHV-8 is contentious^2,3.

• Polymorphic lymphoid proliferations resembling PTLD¹; <5% of HIV-associated lymphomas. EBV is variably present.

• MALT lymphoma is rare

• Peripheral T-cell lymphoma is rare

• NK cell lymphoma is rare

• Plasma cell myeloma with the triad of plasmacytosis, monoclonal gammopathy, and multiple bone lesions has only rarely been reported.

Immunohistochemistry

See the respective lymphoma types.

CD3	may be aberrantly positive in PEL
CD20	lost in plasmablastic DLBCL, PEL and plasmablastic lymphoma of oral cavity
CD30	may be positive in DLBCL and PEL
CD38	may be positive in DLBCL and PEL
CD138 and VS38c	positive in PEL and plasmablastic lymphomas
CD71	may be positive in DLBCL and PEL
EMA	may be positive in DLBCL and PEL

True T-cell lymphomas express CD2, CD3, CD5, and CD4 or CD8; one or more may be lost.

References

World Health Organization Classification of Tumours, Tumours of the haematopoietic and lymphoid tissues, IARC Press 2001.

¹Nador, R.G., Chadburn, A., Gundappa, G., Cesarman, E., Said, J.W. and Knowles, D.M. Human Immunodeficiency Virus (HIV)-Associated Polymorphic Lymphoproliferative Disorders. Am J Surg Pathol 2003;27:293-302.

²Carbone, A., A. Gloghini, et al. (2004). "Is plasmablastic lymphoma of the oral cavity an HHV-8-associated disease?" Am J Surg Pathol 28(9): 1251-2.

³Nuovo, G. J. (2004). "Re: Cioc AM, Allen C, Kalmar J, et al. Oral plasmablastic lymphomas in AIDS patients are associated with human herpesvirus 8. Am J Surg Pathol. 2004;25:41-46." Am J Surg Pathol 28(9): 1252-3.

This page last revised 8.10.2004.

©SMUHT/PW Bishop