A 45 year old, HIV positive patient presents with features of pneumonia. Characteristic histopathological features suggesting pneumocystis carinii pneumonia is:: (A) Prominent Interstitial Pneumonitis, (B) Eosinophilic Alveolar Exudates, (C) Prominent mononuclear cells in Alveolar exudates, (D) Neutrophilic infiltration of alveolar interstitium
Answer is B. Answer is B (Eosinophilic Alveolar Exudate): The most characteristic histoputhological feature of pneumocystis carinii pneumonia in adults is predominantly alveolar, foamy vacuoloted, eosinophilic exudates. Interstitial pneumonitis is usually mild and shows infiltration with PML and mononuclear cells.