(A, B) Female Angiostrongylus costaricensis in an appendix biopsy, stained with hematoxylin and eosin (H&E). Notice the thick, multinucleated intestine (IN), reproductive tubes (RT), eggs (EG) within the uterus (UT), and lateral chords (LC). (C) A. costaricensis eggs in tissue, stained with H&E. (D) A. costaricensis larva in tissue sections stained with H&E.