Case 64. Pneumococcal pneumonia (77 y-o M)
Autopsied lung with lobar pneumonia (three-day clinical course)
Key words : Streptococcus pneumoniae, lobar pneumonia
The middle lobe of the right lung is diffusely solidified and gray-colored (gross findings).   Diffuse intraalveolar exudation of fibrins and neutrophils is observed (HE).
Gram stain identifies a small number of Gram-positive cocci dispersed in the exudates. Cocci are often paired and located outside the neutrophils, indicating the formation of capsule by the bacteria (Gram).