HHV-8/KSHV-negative and CD20-positive primary effusion lymphoma successfully treated by pleural drainage followed by chemotherapy containing rituximab.

The present patient was diagnosed as having human herpes virus-8 (HHV-8)/Kaposi sarcoma herpes virus (KSHV)-negative and CD20-positive primary effusion lymphoma (PEL) of the right-sided pleural effusion. After pleural drainage, malignant cells disappeared spontaneously in a small amount of the remaining pleural effusion without chemotherapy. The patient was treated with six cycles of chemotherapy consisting of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone. He has been in complete remission for more than 22 months. It is suggested that effusion drainage followed by chemotherapy containing rituximab is a potential treatment strategy for patients with HHV-8/KSHV-negative and CD20-positive PEL.