During the autopsy procedure, following a gross examination of the external surfaces, the cut-surfaces of the lungs and examination of the pleural cavities, samples of lung tissue from the apical regions of both the lungs, middle lobe of the right lung, including grossly abnormal areas if found anywhere in the lungs were preserved for further microscopic and molecular examinations at the Department of Pathology, College of Medicine, King Fahd Hospital of the University, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.
Lung specimens for light microscopy were fixed by immersion in 10% neutral buffered formalin for 24–48 h, dehydrated in a graded isopropanol series and embedded in paraffin wax. Paraffin sections of 4 μm thickness were stained with haematoxylin and eosin (H&E) stain and Zeihl–Neelsen (ZN) stain and examined using an Olympus BX51TF light microscope (Olympus Corporation, Tokyo, Japan). H&E-stained sections of the lung tissue were examined for multi-nucleated giant cells and other granulomatous inflammatory findings compatible with tuberculosis. ZN-stained sections of the lung tissue were examined for acid fast bacilli.
Lung specimens for light microscopy were fixed by immersion in 10% neutral buffered formalin for 24–48 h, dehydrated in a graded isopropanol series and embedded in paraffin wax. Paraffin sections of 4 μm thickness were stained with haematoxylin and eosin (H&E) stain and Zeihl–Neelsen (ZN) stain and examined using an Olympus BX51TF light microscope (Olympus Corporation, Tokyo, Japan). H&E-stained sections of the lung tissue were examined for multi-nucleated giant cells and other granulomatous inflammatory findings compatible with tuberculosis. ZN-stained sections of the lung tissue were examined for acid fast bacilli.