title: Primary carcinoids of the ileum and rectum. A simultaneous occurrence.
abstract: A patient had a simultaneous occurrence of an ileal and a rectal carcinoid. The ileal carcinoid, occurring in an area derived from primitive midgut, was argentaffin-positive; the rectal carcinoid, occurring in an area derived from primitive hindgut, was argentaffin-negative. To my knowledge, this is the first reported case of simultaneous ileum and rectal carcinoids; its uniqueness tends to support the concept of heterogeneity of origin of carcinoids in embryologically distinct regions.
mesh_terms: D002276:Carcinoid Tumor / Q000196:embryology / Q000473:pathology*; D006801:Humans; D007082:Ileum / Q000473:pathology; D007414:Intestinal Neoplasms / Q000196:embryology / Q000473:pathology*; D009378:Neoplasms, Multiple Primary / Q000473:pathology*; D012004:Rectal Neoplasms / Q000473:pathology*