title: Benign fibroblastic polyp of the colorectum.
abstract: OBJECTIVE
  We present the clinicopathologic features, endoscopic appearance, and ultrastructure of a newly described mesenchymal polyp of the colorectum, termed benign fibroblastic polyp.
  
  
  METHODS
  A total of 4 cases from our institution are analyzed using routine histopathology, immunohistochemistry, and electron microscopy, and compared with the original series of 14 cases previously described in the pathology literature.
  
  
  RESULTS
  Benign fibroblastic polyps appear endoscopically throughout the colorectum as submucosal lesions with a hyperplastic surface component. These lesions are histologically and ultrastructurally distinct, but overlap with other mesenchymal polyps warrants additional immunohistochemical studies for definitive classification.
  
  
  CONCLUSIONS
  Benign fibroblastic polyps of the colorectum comprise a recently described distinct entity of mesenchymal polyps that appear to follow an indolent clinical course. Their etiology is uncertain but may be linked to an exuberant tissue response following mucosal injury. Gastroenterologists should be aware of this new entity that will be increasingly diagnosed by pathologists.
authors.affiliation: Department of Pathology, University of Vermont College of Medicine, Burlington, VT 05405, USA.
authors.forename: Alexandra N
authors.initials: AN
authors.lastname: Kalof
authors.forename: Bobbi
authors.initials: B
authors.lastname: Pritt
authors.forename: Kumarasen
authors.initials: K
authors.lastname: Cooper
authors.forename: Neil H
authors.initials: NH
authors.lastname: Hyman
authors.forename: Hagen
authors.initials: H
authors.lastname: Blaszyk
mesh_terms: D000199:Actins / Q000378:metabolism; D000368:Aged; D018952:Antigens, CD34 / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D003111:Colonic Polyps / Q000378:metabolism / Q000473:pathology*; D016099:Endoscopy, Gastrointestinal; D005260:Female; D005347:Fibroblasts; D005500:Follow-Up Studies; D006801:Humans; D006965:Hyperplasia / Q000378:metabolism; D007150:Immunohistochemistry; D007417:Intestinal Polyps / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D012002:Rectal Diseases / Q000378:metabolism / Q000473:pathology*; D009418:S100 Proteins / Q000378:metabolism
chemical_list: D000199:Actins; D018952:Antigens, CD34; D015415:Biomarkers; D009418:S100 Proteins; D019009:Proto-Oncogene Proteins c-kit