Human herpes virus 8 associated primary effusion lymphoma in HIV-negative patients: A distinct clinical entity? A distinct clinical entity?

Primary effusion lymphoma (PEL) is a recently described rare type of non-Hodgkin's lymphoma, occurring almost exclusively in HIV- infected people. It is characterized by the presence of malignant effusions with no lymphadenopathy and carries a very poor prognosis. Human herpes virus 8 (HHV-8), first described as a viral particle associated with Kaposi's sarcoma (KS), has been linked with PEL, and a causative relationship has been suggested. In a vast majority of PEL cases Epstein-Barr virus has been found in the tumor cells. We describe here an elderly HIV-negative man with intractable "pleuritic"chest pain and pleural effusion. The diagnosis of a diffuse large B cell malignant lymphoma has been suggested cytologically and confirmed histologically, following pleural biopsy. No lymphadenopathy or organ involvement with lymphoma was found. The presence of HHV-8 has been demonstrated in the tumor cells by PCR analysis, using paraffin-embedded tissue samples from the involved pleura, whereas EBV-related genes were absent. The diagnosis of PEL was therefore established. Systemic chemotherapy with dose-modified CHOP regimen with G-CSF support gradually led to the resolution of the chest pain and ultimately resulted in a complete clinical remission (CCR). The patient remained in CCR for 18 months and died of an unrelated cause (cerebrovascular event). Only 11 other cases with clinical and virological features similar to those of our patients were reported in the literature. Analysis of these rare cases suggests HIV-negative EB V-negative PEL to be a distinct clinical entity with epidemiological features resembling classical KS, and supports an EBV-independent role for HHV-8 in the pathogenesis of this type of lymphoma. A favorable response of PEL to combination chemotherapy is reported -for the first time, to the best of our knowledge.