Diagnosis of human sarcocystis infection from biopsies of the skeletal muscle.

Sarcocystis is an uncommon parasitic infection. We report four cases that presented with lumps, pain in the limbs or a discharging sinus of unknown etiology. Microscopic examination of the excised tissue in all cases showed characteristic cysts of the sarcocystis parasite. A discussion of the identification and recognition of this uncommon infection from muscle biopsies is given.