<prompt> 20 years old Rajesh presence with fever and chronic cough ESR 35 mm sputum cytology is negative for AFB and tuberculin test show indurations of 19 X 23 mm. The probable diagnosis is -Fungal pneumoniaViral pneumoniaPulmonary T.B.Bacterial pneumonia  <response>: Ans. is c i.e., Pulmonary T.B. o The history and tuberculin test strongly suggests the diagnosis of T.B. o Do not get confused by negative sputum cytology because negative sputum cytology does not rule out pulmonary tuberculosis. Sputum cytology is just a presumptive diagnosis - Harrison The definitive diagnostic of T.B. depends upon the culture of bacteria obtained from respiratory specimen - Harrison o The presence of induration 15 mm in size strongly indicates T.B. infection. 