title: "Crawling-type" adenocarcinoma of the stomach: a distinct entity preceding poorly differentiated adenocarcinoma.
abstract: BACKGROUND
  Gastric "crawling-type" adenocarcinoma (CTAC) is a neoplasm histologically comprising irregularly fused glands with low-grade cellular atypia that tends to spread laterally in the mucosa. It is necessary to elucidate the clinicopathological characteristics of CTAC.
  
  
  METHODS
  We evaluated 25 CTACs-16 intramucosal (M-) and 9 submucosal invasive (SM-) cancers-clinicopathologically and immunohistochemically.
  
  
  RESULTS
  CTAC was most frequently located in the lesser curvature of the middle-third of the stomach. Macroscopically, 21 lesions were superficial-depressed and 4 were superficial-flat type. Histologically, all CTACs had cystic dilated glands and 16 lesions had focal signet-ring cells. All invasive areas of the SM-CTACs were occupied by poorly differentiated adenocarcinoma with an infiltrative growth pattern and abundant stroma. Fifteen CTACs were surrounded by mucosa with partial or no intestinal metaplasia. In the intramucosal area, 24 lesions were mixed phenotype with mucin and brush border immunoexpression. SM-CTAC was frequent in lesions with an intramucosal poorly differentiated component (PDC) greater than 10 mm in size (P = 0.041), and lymph node metastasis (LNM) was frequent in lesions with a PDC greater than 20 mm (P = 0.039). The frequency of an expanded pattern (Ki-67-positive cells occupying > 50 % of the mucosa) was higher in SM-CTAC than in M-CTAC (P = 0.027). p53 overexpression was not detected in the intramucosal areas of any of the lesions.
  
  
  CONCLUSIONS
  CTAC is a distinct subgroup of gastric adenocarcinoma in the early phase. A larger PDC and a Ki-67 expanded pattern were predictive of submucosal invasion or LNM.
authors.affiliation: Department of Human Pathology, Tokyo Medical and Dental University, Yushima 1-5-45, Tokyo, 113-8519, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Okamoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawachi
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Yoshida
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kitagaki
authors.forename: Masaki
authors.initials: M
authors.lastname: Sekine
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Kojima
authors.forename: Tatsuyuki
authors.initials: T
authors.lastname: Kawano
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Eishi
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000071616:CDX2 Transcription Factor; D002454:Cell Differentiation; D005260:Female; D005753:Gastric Mucosa / Q000473:pathology*; D018398:Homeodomain Proteins / Q000032:analysis / Q000378:metabolism; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis / Q000378:metabolism; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008871:Microvilli / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D009077:Mucins / Q000378:metabolism; D010641:Phenotype; D013274:Stomach Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D016159:Tumor Suppressor Protein p53 / Q000032:analysis / Q000378:metabolism
chemical_list: D000071616:CDX2 Transcription Factor; C491270:CDX2 protein, human; D018398:Homeodomain Proteins; D019394:Ki-67 Antigen; D009077:Mucins; D016159:Tumor Suppressor Protein p53