Diverse clinicopathologic features in human herpesvirus 8-associated lymphomas lead to diagnostic problems

Objectives: Human herpesvirus 8 (HHV8)-associated lymphomas are uncommon, mainly affect men infected with the human immunodeficiency virus (HIV), and usually have a poor prognosis. We sought to characterize the HHV8+ lymphomas seen at our institution since the mid-1990s. Methods: We identified 15 patients with HHV8-associated lymphomas and evaluated their clinical and pathologic features. Results: Diagnoses included primary effusion lymphoma (PEL) (n = 2), extracavitary PEL (n = 8), intravascular large B-cell lymphoma (n = 1), HHV8+ plasmablastic microlymphoma (n = 3), and germinotropic lymphoproliferative disorder (GLD) (n = 1). The case of GLD progressed to a high-grade HHV8+ Epstein-Barr virus-positive lymphoma, an evolution that has not been previously reported. Four patients were HIV- (three from an HHV8-endemic area). Potentially misleading pathologic features in our series of extracavitary PEL included classic Hodgkin lymphoma-like features, lymph node sinus involvement, and T-cell antigen expression. Conclusions: HHV8-associated lymphomas can be clinically and pathologically heterogeneous, with features that may lead to misdiagnosis as other types of lymphoma.