[A case of natural killer cell lymphoma with high adenosine deaminase level in pleural effusion]

A 61-year-old man was admitted to our hospital with cough, breathlessness, anorexia and chest pain. Chest radiograph showed right pleural effusion and also a chest CT scan showed right pleural effusion with thickening of the right visceral pleura, pericardial effusion and a liver tumor. The pleural effusion was slightly bloody and exudative. The adenosine deaminase (ADA) level in the pleural effusion was elevated. Because the cytological examintion of the pleural effusion showed no malignancy, we diagnosed pleuritis tuberculosa. The serum-soluble interleukin-2 receptor level was also elevated. His general condition worsened in spite of the chemotherapy with antibiotics and antituberculous drugs. We finally diagnosed the case as natural killer (NK) cell lymphoma from CT-guided needle biopsy just before death, and necropsy. In this case, the high level of ADA in the pleural effusion suggested lymphoma.