[Primary pleural non-Hodgkin's lymphoma without chronic pyothorax]

Most cases of primary pleural malignant lymphoma develop following chronic pyothorax. We report a case of primary pleural non-Hodgkin's lymphoma without chronic pyothorax. A 63-year-old woman was referred and admitted to our hospital with a right pleural effusion that was detected during a routine physical checkup. Her liver, spleen, and superficial lymph nodes were not palpable on physical examination. The massive right pleural effusion and a pleural mass were demonstrated on chest X-ray films and thoracic computed tomograms. Diffuse large B-cell non-Hodgkin's lymphoma was diagnosed by needle biopsy from the pleura, and the clinical stage was IE. Pleural effusion specimens contained no identifiable lymphoma cells, and examinations for Mycobacterium species were also negative. Human herpes virus 8 (HIV-8) DNA was detected in lymphocytes from the peripheral blood and pleural effusion. Epstein-Barr virus-encoded small RNAs and HHV-8 DNA were both negative in biopsied tissue from the pleural mass. Although a complete remission was achieved, the lymphoma relapsed about 8 months later. The patient is currently receiving salvage chemotherapy. Cases of primary pleural non-Hodgkin's lymphoma with massive pleural effusion that are not preceded by chronic pyothorax or Kaposi's sarcoma are very rare.