My father suffering from Pneumonia has patches still persisting in the upper lobe of his left lungs ?

My father is 76 yrs old and has been admitted in hospital. He was detected with pneumonia. X ray and Scan of Thorax (CRCT) was done which still shows some patch. Antibiotic dose are over, but the doctor is still not sure about the patch. He is terribly weak and is unable to sit up. He is still in hospital. He has cough but it is not coming out. Doc's suggest FNAC and other test to rule out TB or Cersonogenic development. He had fever about 100 degrees Celsius yesterday. What can be the possible result ? Please advise.