Non-Hodgkin lymphoma with high adenosine deaminase levels mimicking peritoneal tuberculosis: an unusual presentation.

Abdominal tuberculosis is still a medical problem in developing countries. The clinical presentation of tuberculous (TB) peritonitis may be similar to that of peritoneal carcinomatosis. Therefore, its diagnosis is rather difficult only with laboratory investigations. Ascitic fluid adenosine deaminase (ADA) activity has been proposed as a useful diagnostic test in tuberculous peritonitis, as many studies reported high ADA levels in TB peritonitis. On the other hand, ADA activity is usually lower in peritoneal carcinomatosis and malignant ascites. This study described a patient with non-Hodgkin lymphoma with elevated (67 U L(-1)) ADA levels and clinical signs mimicking peritoneal tuberculosis. On admission, this study focused on the high value of ADA in ascites and strongly suspected TP. Although anti-tuberculous agents were initiated, his general condition did not improve. Finally, laparoscopic peritoneal biopsy was performed and non-Hodgkin lymphoma diagnosed. In the light of these findings, ADA level may not reflect TB peritonitis in the absence of histopathological examination. Therefore, non-Hodgkin lymphoma should be kept in mind in the differential diagnosis in patients with high ascitic fluid ADA levels and in non-responders to anti-tuberculosis treatment.