Sarcocystosis biopsy

A single sarcocyst (arrow) within a muscle fiber. Bar = 40 microns. H&E stains, 620 objective lens. Typically, perivascular inflammation occurs within the endomysium and perimysium. The severity ranges from occasional foci of predominantly lymphohistiocytic infiltrate to more widespread foci of mixed inflammation. As visible sarcocysts are widely scattered within inflamed tissue, biopsies may demonstrate myositis only despite serial sections.