Acute inflammation of the walls of the terminal bronchioles that spreads into the peribronchial alveoli and alveolar ducts. It results in the creation of foci of consolidation, which are surrounded by normal parenchyma. It affects one or more lobes, and is frequently bilateral and basal. It is usually caused by bacteria (e.g., Staphylococcus, Streptococcus, Haemophilus influenzae). Signs and symptoms include fever, cough with production of brown-red sputum, dyspnea, and chest pain. [from
NCI]