Fig. 3
From: Tropheryma whipplei infection in the lung of a patient with long COVID: a case report
Hematoxylin and eosin staining (A: low-power photomicrograph; B: original magnification×100) showing the interstitial pneumonia with lymphocyte and plasmacyte infiltration of the alveolar septum and focal proliferation of fibrous tissue. Numerous foamy macrophages are seen in the alveolar air space. The foamy macrophages stained positive for CD68 by immunohistochemistry (C). Periodic acid-Schiff staining showing numerous intracytoplasmic organisms (black arrows), with morphologic features consistent with T. whipplei (original magnification× 200 (D)