True statement regarding pathology of pneumocystis jiroveci pneumonia:

Ans: A (Alveoli is filled with foamy exudates) Ref: Rubin's Pathology: Clinicopathologic Foundations of Medicine, 6th edition, pg 554Explanation:Pathology of Pneumocystis Jiroveci Pnuemonia* The classic lesion of pneumocystis pneumonia are:o interstitial infiltrate of plasma cells and lymphocytes.o Hyperplasia of type 2 pneumocytes.Alveoli are filled with a characteristic foamy exudate, in which the organism appear as small hubbies in a background of proteinaceous exudates.With silver impregnation, cysts appear as round or indented (Crescent moon) bodies, 5 microns in diameter.A darkly stained focus represents focal thickening of the capsule.After sporozoites develop within the cyst, it ruptures and assumes an indented shape.Sporozoites develop into trophozoites, which may be seen with stains such as Giemsa in cytology specimens.Granulomatous inflammation is rare but seen in upto 5% HIV patients.Rarely, diffuse alveoar damage is seen.Chest X-ray FindingsDiffuse bilateral infiltrates extending from the perihilar region are visible in most patients with P jiroved pneumonia (PJP).Less-common findings include patchy asymmetric infiltrates and pneumatoceles.Pleural effusions and /r?fraf/iorac/c adenopathy are rare.