title: Comparison between colorectal low- and high-grade mucinous adenocarcinoma with MUC1 and MUC5AC.
abstract: OBJECTIVE
  To explore useful prognostic factors for mucinous adenocarcinoma (MAC) in the colon and rectum.
  
  
  METHODS
  MAC was divided into low- and high-grade types based on the degree of structural differentiation; low-grade MAC arisen from well to moderately differentiated adenocarcinoma and papillary carcinoma, and high-grade MAC from poorly differentiated adenocarcinoma and signet ring cell carcinoma. Immunohistochemically, the expression of 2 types of MUC1 (MUC1/DF and MUC1/CORE), MUC2, 2 types of MUC5AC (MUC5AC/CHL2 and HGM), MUC6, CDX2, and CD10 was examined in 16 cases of MAC consisting of 6 low- and 10 high-grade types.
  
  
  RESULTS
  MUC1/DF3 was expressed in 3 of 6 low-grade MAC (50%) and 10 of 10 high-grade MAC (100%). MUC1/CORE was expressed in 1 of 6 low-grade MAC (16.7%) and 7 of 10 high-grade MAC (70%). MUC2 was expressed in all MAC regardless of the grade. MUC5AC was expressed in 6 of 6 low-grade MAC (100%) and 4 of 10 high-grade MAC (40%). HGM was expressed in 5 of 6 low-grade MAC (83.3%) and 6 of 10 high-grade MAC (60%). Expression of MUC6 and CD10 was undetected in all MAC regardless of the grade. CDX2 was expressed in 5 of 6 low-grade MAC (83.3%) and 7 of 10 high-grade MAC (70%). Taken together, MUC1/DF3 was expressed significantly more frequently in high-grade MAC than in low-grade, and MUC5AC/CHL2 was expressed significantly more frequently in low-grade MAC than in high-grade.
  
  
  CONCLUSIONS
  It is proposed that MUC1/DF3 and MUC5AC/CHL2 immunostaining is useful to discriminate high-grade MAC from low-grade MAC.
authors.affiliation: Masayuki Onodera, Takashi Nishigami, Ikuko Torii, Ayuko Sato, Li-Hua Tao, Tatsuki R Kataoka, Tohru Tsujimura, Department of Pathology, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Onodera
authors.forename: Takashi
authors.initials: T
authors.lastname: Nishigami
authors.forename: Ikuko
authors.initials: I
authors.lastname: Torii
authors.forename: Ayuko
authors.initials: A
authors.lastname: Sato
authors.forename: Li-Hua
authors.initials: LH
authors.lastname: Tao
authors.forename: Tatsuki R
authors.initials: TR
authors.lastname: Kataoka
authors.forename: Reigetsu
authors.initials: R
authors.lastname: Yoshikawa
authors.forename: Tohru
authors.initials: T
authors.lastname: Tsujimura