Background: Primary cavity-based lymphomas (PCBL) represent and uncommon group on non-Hodgkin lymphomas associated with AIDS. They present as malignant effusions with no bone marrow or lymph node involvement, although some cases with bone marrow infiltration at advanced stages have been reported. Tumoral cells are monoclonal and are occasionally infected with human herpesvirus type-8 (HHV-8).
Patients and methods: The clinical and evolutive characteristics of six HIV-positive patients with PCBL were analysed. In three of them the presence of genetic sequences of HHV-8 in peripheral blood lymphocytes and lymphomatous effusions was investigated by PCR.
Results: The mean age of patients was 37 years and 5 were males. The only female patient had been drug abuser, four males were homosexuals and the other promiscuous heterosexual. The mean CD4+ lymphocyte count was 84 x 10(6)/l (range: 20-180) and all of them had been diagnosed of AIDS. The presentation forms were as pericardial effusion in one case, pleural effusion in three and tumoral ascites in two. Two of the male patients had also Kaposi sarcoma (KS). At diagnosis none of them had infiltration of the bone marrow nor lymphadenopathy. Most malignant cells had immunoblastic traits. The effusions had the characteristics of an exudate and the mean value of lactate dehydrogenase (LDH) was 5,255 IU/l (range: 1,500-11,483). In the three cases investigated there was HHV-8 DNA in the lymphocytes present in the lymphomatous effusion and in peripheral blood. The mean survival after diagnosis was 89 days (7-240). The female patient died without therapy seven days after admission and the five male patients were treated with chemotherapy with a poor response.
Conclusions: HIV-related PCBL associated or not with KA appear in severely immunodepressed patients, their behaviour is very aggressive and its clinical course fatal in a short period of time. The are often associated with KS and HHV-8 seems to be the involved causative agent.