The study was carried out on 50 patients selected from chestdepartment, Cairo University and Giza chest hospital. They were dividedinto 4 groups according to the diagnosis, group (1): tuberculosis patientspositive for AFB by microscopic examination, group (2): cancer patients,confirmed histopathologically. Group (3): pneumonia patients and group(4): normal persons. All patients were subjected to thorough history taking and clinicalexamination, Plain chest x-ray (Postero anterior and Lateral View),Sputum examination for Acid Fast Bacilli (AFB), Routine laboratoryInvestigations including: Complete Blood Count & differential count,liver & renal function tests and Adenosine deaminase (ADA) in serum andbroncho alveolar lavage fluid BALF.