title: Expression of CD24, a Stem Cell Marker, in Pancreatic and Small Intestinal Neuroendocrine Tumors.
abstract: OBJECTIVE
  CD24 has been considered a normal and cancer stem cell marker. Potential intestinal stem cells weakly express CD24. In the pancreas, CD24 is a possible cancer stem cell marker for ductal adenocarcinoma.
  
  
  METHODS
  Expression of CD24 in intestinal and pancreatic neuroendocrine tumors (NETs) was examined. Immunohistochemistry was performed on benign duodenum, ileum mucosa, and pancreas, as well as primary duodenal, primary and metastatic ileal, and pancreatic NETs.
  
  
  RESULTS
  Scattered CD24-positive cells were noted in the duodenal and ileal crypts, most of which showed a strong subnuclear labeling pattern. Similar expression was observed in 41 (95%) of 43 primary ileal NETs but in only four (15%) of 26 duodenal NETs (P < .01). In addition, metastatic ileal NETs retained CD24 expression. Pancreatic islets did not express CD24, and only rare cells had subnuclear labeling of CD24 in the pancreatic ducts. Unlike ileal NETs, only five (5%) of 92 pancreatic NETs expressed CD24 in the subnuclear compartment (P < .01). All five NETs showed a unique morphology with prominent stromal fibrosis.
  
  
  CONCLUSIONS
  CD24 expression was frequent in primary and metastatic midgut NETs but rare in pancreatic and duodenal NETs. Expression of CD24 in ileal NETs may have future diagnostic and therapeutic implications.
authors.affiliation: From the Departments of Pathology, Microbiology, and Immunology; Safia.n.salaria@vanderbilt.edu.
authors.forename: Safia
authors.initials: S
authors.lastname: Salaria
authors.affiliation: Surgery; and.
authors.forename: Anna
authors.initials: A
authors.lastname: Means
authors.affiliation: From the Departments of Pathology, Microbiology, and Immunology;
authors.forename: Frank
authors.initials: F
authors.lastname: Revetta
authors.affiliation: Surgical Oncology, Vanderbilt University Hospital, Nashville, TN.
authors.forename: Kamran
authors.initials: K
authors.lastname: Idrees
authors.affiliation: Surgical Oncology, Vanderbilt University Hospital, Nashville, TN.
authors.forename: Eric
authors.initials: E
authors.lastname: Liu
authors.affiliation: From the Departments of Pathology, Microbiology, and Immunology;
authors.forename: Chanjuan
authors.initials: C
authors.lastname: Shi
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D051927:CD24 Antigen / Q000032:analysis / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D007414:Intestinal Neoplasms / Q000473:pathology*; D014411:Neoplastic Stem Cells / Q000473:pathology*; D018358:Neuroendocrine Tumors / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor; D051927:CD24 Antigen; C497889:CD24 protein, human
keywords: CD24; Gastrointestinal; Neuroendocrine tumor; Pancreas; Small intestine; Stem cell marker