Hi... Thanks for contacting HCM for health query.. You are asking on behalf of an elderly lady who had cough evaluated with CTscan chest who has bilateral infiltration and you are worried about cancer. Bilateral extensive cancer at the time of presentation is quite rare though it can occur. If I have a patient like this in my outpatient department I would now proceed on with bronchoscopic guided aspiration and biopsy subject the aspirate for cytology,cell count and culture.I would also do blood investigation like complete blood count and others keeping in mind infection like tuberculosis,occupational lung diseases like asbestosis and post infective bronchiectasis etc. Do not be worried.. Till forth give her a protein and fat rich food (fatty foods are good for respiratory problems) give her good aerated room and handle her sputum with caution. Take care.