KSHV-positive solid lymphomas represent an extra-cavitary variant of primary effusion lymphoma

Area of Science:

• Oncology
• Virology
• Pathology

Background:

• Primary effusion lymphoma (PEL) is a distinct non-Hodgkin lymphoma (NHL) linked to Kaposi sarcoma-associated herpesvirus (KSHV; HHV-8).
• Rare KSHV-positive lymphomas in solid tissues have been observed, but their relationship to PEL remains unclear.

Purpose of the Study:

• To investigate the features of KSHV-positive solid lymphomas.
• To compare these solid lymphomas with PEL to determine if they represent a spectrum of the same disease.

Main Methods:

• Systematic investigation of morphologic, immunophenotypic, and molecular features of 8 KSHV-positive solid lymphomas from HIV+/AIDS patients.
• Comparison of these cases with 29 PEL cases using identical analytical methods.

Main Results:

• KSHV-positive solid lymphomas were morphologically and molecularly indistinguishable from PELs.
• Minor differences in B cell antigen and immunoglobulin expression were noted but not statistically significant.
• Patients with solid lymphomas had similar clinical courses but lacked effusions and showed a trend towards better survival, especially with anti-retroviral therapy.

Conclusions:

• KSHV-positive solid lymphomas share key characteristics with PEL.
• These solid lymphomas are proposed to be a variant of PEL, termed extra-cavitary PEL.
• The findings suggest a broader spectrum for KSHV-associated lymphomas than previously recognized.