Features of pneumocystic carini pneumonia are:

Answer is D (All of the above) Pneumocytic carinii pneumonia is charachterized by a prominent eosinophilic exudate and mild interstitial pneumonitis. These is damage to type I pneumocytes and associated compensatory hyperophy of type II pneumocytes. Classic Histopathology in Pneumocystis Pneumonia lntra- Alveolar Changes Prominent Eosinophilic foamy, vacuolated intraalveolar exudate (HE staining) Intra alveolar exudate contains the organisms, which can be identified in various stages of development (trophozoite and cystic stage) by the use of special stains such as Methamine silver / Toluidine stain Wright Giemsa stain Papanicolaou's stain Intraalveolar exudate also contains host serum proteins, debris, & surfactant proteins Alveolar macrophages are present but not prominent in phagocytosis of organism. The principle host effector cells against pneumocystis are alveolar macrophages which ingest & kill the organism Interstitial Changes Mild interstitial Pncumonitis Mononuclear interstitial cell infiltrate (mild) Damaged type I Pneumocytes Hyperophy /proliferation of type II pneumocytis (Reparative response) Pneumocystis attaches to, and damages type I pneumocytes. There is associated compensatory hyperophy of type II pneumocytes. Note: Most compromised hosts display a mild mononuclear interstitial cell infiltrate however malnourished children display an intense interstitial plasma cell infiltrate which was responsible for the diseases early name of interstitial plasma cell pneumonia'