title: Mixed adenocarcinoma-carcinoid (collision tumor) of the appendix.
abstract: OBJECTIVE
  To report a case of mixed adenocarcinoma and carcinoid in the gastrointestinal tract.
  
  
  METHODS
  A 52-year-old man presented with a mass at the base of the appendix. On microscopic examination of the tumor, mixed adenocarcinoma and carcinoid was identified. The carcinoid component was insular/trabecular in morphology, and the epithelial component revealed mucinous adenocarcinoma. Morphologically and immunohistochemically the 2 components showed a clear-cut distinction, without any intervening intermediate cell population. The adenocarcinomatous component displayed omental deposit and metastasis to the regional lymph nodes. One year later, the patient developed multiple metastatic deposits of adenocarcinoma in the liver, rectus muscle, ileum and sigmoid colon.
  
  
  CONCLUSIONS
  This tumor had an aggressive clinical course and behaved more like adenocarcinoma than carcinoid.
authors.affiliation: Department of Pathology, Al-Jahra Hospital, Al-Jahra, Kuwait. gopen71@yahoo.co.in
authors.forename: Naorem Gopendro
authors.initials: NG
authors.lastname: Singh
authors.forename: Abul Ala Syed Rifat
authors.initials: AA
authors.lastname: Mannan
authors.forename: Mirza
authors.initials: M
authors.lastname: Kahvic
authors.forename: Ali Mohamd
authors.initials: AM
authors.lastname: Nur
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D001063:Appendiceal Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D001065:Appendix / Q000473:pathology* / Q000601:surgery; D002276:Carcinoid Tumor / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D017809:Fatal Outcome; D006801:Humans; D008297:Male; D008875:Middle Aged