Other Manifestations of Pneumocystis Infection

A

Miliary granulomas were found in the biopsy of another patient with chronic lymphocytic leukemia not on pneumocystis prophylaxis. Note the apparent necrotic center surrounded by epithelioid cells and fibrosis mixed with scattered lymphoid cells. At higher power, the "necrotic" center appeared foamy. A GMS stain showed pneumocystis spore cases confined to the central pink area.

B

Granulomatous inflammation with calcification: An AIDS patient with chronic pneumocystis pneumonia had scattered fibrotic nodules with multiple, plate-like calcifications (arrow shows one) and a heavy lymphoid infiltrate. A GMS stain showed pneumocystis spore cases in the calcified regions. Several multinucleated giant cells are present around the asterisk.

Extrapulmonary Pneumocystis

C

Pneumocystis hepatitis: This section of liver from an AIDS patient with disseminated pneumocystis infection shows the typical foamy exudate replacing liver cells. The exudate shows focal calcification (arrow). Note the lack of inflammation.

Calcifications in pneumocystis infections: The calcifications associated with pneumocystis have been classified descriptively as bubbly, plate-like, conchoidal, or elongate. The two examples shown here illustrate plate-like (B) and bubbly calcifications (arrow) (C). Both represent dystrophic calcification of necrotic tissue in which spore cases can be identified with the GMS stain. In B, they are present in a fibrotic lesion, whereas in C they are present in active, foamy exudate. These calcifications should suggest the diagnosis of pneumocystis infection when it is not suspected [1].

Reference

1. Lee M, Schinella R. Pulmonary calcification caused by Pneumocystis carinii pneumonia. A clinicopathological study of 13 cases in acquired immune deficiency syndrome patients. Am J Surg Pathol 1991; 15:376-380.

Clinical summary Discussion

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