title: Gastric carcinoid in the absence of atrophic body gastritis and with low Ki67 index: a clinical challenge.
abstract: BACKGROUND
  Gastric carcinoids (GCs) represent 23% of all digestive neuroendocrine tumors (NETs). They can be distinguished into three types: type I (in the presence of atrophic body gastritis, ABG), type II (in the presence of Zollinger-Ellison/multiple endocrine neoplasia type I syndrome), type III (sporadic carcinoids, without any background pathology).
  
  
  OBJECTIVE
  To describe a case of undetermined type of GCs in an Italian referral center for NETs and its prevalence among GCs during a 6-year period.
  
  
  RESULTS
  In a case series of 16 GCs seen at our unit between 2007 and 2012, 14 (83.3%) patients had type I carcinoid and 1 patient (6.2%) had type III carcinoid. One patient did not accomplish to the actual classification criteria. This patient had a well-differentiated carcinoid with low Ki67, but multiple gastric biopsies performed at 3-year follow-up gastroscopies excluded the presence of ABG. The patient had fundic cystic polyps, suggesting long-term use of proton pump inhibitors, possibly associated with GCs.
  
  
  CONCLUSIONS
  This case shows that a GC may occur in the absence of ABG and with low Ki67 index, making classification according to actual criteria difficult. Further studies are needed to better understand the occurrence of this particular type of GCs.
authors.affiliation: Department of Digestive and Liver Disease, Sant'Andrea Hospital, II Medical School, Sapienza University , Rome , Italy.
authors.forename: Edith
authors.initials: E
authors.lastname: Lahner
authors.forename: Emanuela
authors.initials: E
authors.lastname: Pilozzi
authors.forename: Gianluca
authors.initials: G
authors.lastname: Esposito
authors.forename: Gloria
authors.initials: G
authors.lastname: Galli
authors.forename: Bruno
authors.initials: B
authors.lastname: Annibale
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D002276:Carcinoid Tumor / Q000737:chemistry / Q000145:classification / Q000175:diagnosis* / Q000473:pathology; D016145:Endoscopy, Digestive System; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007558:Italy; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000737:chemistry / Q000145:classification / Q000175:diagnosis* / Q000473:pathology
chemical_list: D019394:Ki-67 Antigen