title: CDX-2 expression in pseudomyxoma peritonei: a clinicopathological study of 42 cases.
abstract: OBJECTIVE
  CDX-2 is a highly sensitive and specific marker of intestinal epithelial cells and their neoplastic counterparts. CDX-2 status in pseudomyxoma peritonei (PMP) has been barely reported. The aim of this study was to investigate the clinicopathological features of 42 cases of PMP with a special emphasis on CDX-2.
  
  
  RESULTS
  All patients were treated by cytoreduction. Immunohistochemistry was performed for CDX-2, MUC-2, MUC-5AC, cytokeratin (CK) 7 and CK20. Statistical correlation was evaluated for age, sex, completeness of cytoreduction and histological subtype with overall and progression-free survival (OS and PFS). PMP consisted of 32 cases of disseminated peritoneal adenomucinosis and 10 cases of peritoneal mucinous carcinomatosis. The appendix evaluated in 25 cases showed two mucinous adenocarcinomas and 21 low-grade appendiceal mucinous neoplasms. CDX-2 was diffusely positive in 40 cases, with the remaining two cases being focally positive. All cases demonstrated diffuse reactions to CK20 and MUC-2, and variable reactions to MUC-5AC, while CK7 was variably positive in 38 cases. Five-year OS was 97%. Histological type was significantly correlated with PFS (P=0.02).
  
  
  CONCLUSIONS
  CDX-2 is diffusely and strongly positive in PMP. This is a useful marker to confirm an appendiceal origin of PMP, particularly when used in conjunction with CK7, CK20, MUC-2 and MUC-5AC.
authors.affiliation: Department of Pathology, New York University Medical Center, New York, NY 10016, USA. daisuke.nonaka@med.nyu.edu
authors.forename: D
authors.initials: D
authors.lastname: Nonaka
authors.forename: S
authors.initials: S
authors.lastname: Kusamura
authors.forename: D
authors.initials: D
authors.lastname: Baratti
authors.forename: P
authors.initials: P
authors.lastname: Casali
authors.forename: R
authors.initials: R
authors.lastname: Younan
authors.forename: M
authors.initials: M
authors.lastname: Deraco
mesh_terms: D000328:Adult; D000368:Aged; D001063:Appendiceal Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D014408:Biomarkers, Tumor / Q000032:analysis*; D000071616:CDX2 Transcription Factor; D002276:Carcinoid Tumor / Q000473:pathology; D018572:Disease-Free Survival; D005260:Female; D018398:Homeodomain Proteins / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D053554:Keratin-20; D053552:Keratin-7; D007633:Keratins / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D055271:Mucin 5AC; D055262:Mucin-2; D009077:Mucins / Q000378:metabolism; D009378:Neoplasms, Multiple Primary / Q000378:metabolism / Q000473:pathology; D010534:Peritoneal Neoplasms / Q000145:classification / Q000378:metabolism* / Q000473:pathology; D011379:Prognosis; D011553:Pseudomyxoma Peritonei / Q000145:classification / Q000378:metabolism* / Q000473:pathology; D012189:Retrospective Studies; D016019:Survival Analysis; D015534:Trans-Activators / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D000071616:CDX2 Transcription Factor; D018398:Homeodomain Proteins; C507499:KRT20 protein, human; C507497:KRT7 protein, human; D053554:Keratin-20; D053552:Keratin-7; C524625:MUC2 protein, human; C524678:MUC5AC protein, human; D055271:Mucin 5AC; D055262:Mucin-2; D009077:Mucins; D015534:Trans-Activators; D007633:Keratins