Bronchointerstitial Pneumonia

• May be considred as a variation of bronchopneumonia
• A hybrid of bronchopneumonia and interstitial pneumonia in which the interstitial inflammation (inflammation of alveolar walls) is restricted to alveoli in the vicinity of terminal bronchioles from which the infections spread
• Like broncho-pneumonia it is most common in cranioventral lobes
• Inhaled mycoplasmas and some viruses
• Initial inflammatory reaction occurring in the bronchioles, but its main expression being an interstitial lymphocytic proliferation, often to the extent of forming complete lymphoid follicles around the airways - a cell-mediated response to chronic persistent antigenic challenge