Sarcocystis infection and actinomycosis in tumorous eosinophilic enterocolitis.

Intramural masses were resected from jejunum and ileocecal portion of a 49-year-old, female patient with partial gut obstruction. Histopathological examination indicated the masses to be tumorous eosinophilic enterocolitis. Recent and late development phases of Sarcocystis in relation to bradyzoite infection have been observed and considered to be responsible for eosinophilic inflammation. Concomitant intestinal actinomycosis, known to produce tumorous lesion without eosinophilia, appears as an attractive natural model in producing tumorous eosinophilic enterocolitis. Pertaining to parasitic development, it is suggested that persisting sporulated oocyst may undergo spontaneous excystation in the host's intestinal wall, along with complex sporogony.