title: Inclusion of MUC1 (Ma695) in a panel of immunohistochemical markers is useful for distinguishing between endocervical and endometrial mucinous adenocarcinoma.
abstract: BACKGROUND
  Distinguishing endocervical adenocarcinoma (ECA) from endometrial mucinous adenocarcinoma (EMMA) is clinically significant in view of the differences in their management and prognosis. In this study, we used a panel of tumor markers to determine their ability to distinguish between primary endocervical adenocarcinoma and primary endometrial mucinous adenocarcinoma.
  
  
  METHODS
  Immunohistochemistry using monoclonal antibodies to MUC1 (Ma695), p16, estrogen receptor (ER), progesterone receptor (PR), and vimentin, was performed to examine 32 cases, including 18 EMMAs and 14 ECAs. For MUC1, cases were scored based on the percentage of staining pattern, apical, apical and cytoplasmic (A/C), or negative. For p16, cases were scored based on the percentage of cells stained. For the rest of the antibodies, semiquantitative scoring system was carried out.
  
  
  RESULTS
  For MUC1, majority of EMMA (14 of 18 cases, 78%) showed A/C staining, whereas only few ECA (2 of 14, 14%) were positive. The difference of MUC1 expression in the two groups of malignancy was statistically significant (p < 0.001). Staining for p16 was positive in 10 of 14 (71%) ECA and 4 of 18 (22%) EMMA. Estrogen receptor was positive in 3 of 14 (21%) ECA and 17 of 18 (94%) EMMA. Progesterone receptor was positive in 3 of 14 (21%) ECA and 16 of 18 (89%) EMMA. Vimentin was positive in 1 of 14 (7%) ECA, and 9 of 18 (50%) EMA, with median and range of 0 (0-6), and 1.5 (0-9) respectively.
  
  
  CONCLUSIONS
  A panel of immunohistochemical markers including MUC1, p16, ER, PR, and vimentin is recommended, when there is morphological and clinical doubt as to the primary site of endocervical or endometrial origin.
authors.affiliation: Department of Pathology, Roswell Park Cancer Institute, State University of New York at Buffalo, NY, USA. tk14216@yahoo.com
authors.forename: Thaer
authors.initials: T
authors.lastname: Khoury
authors.forename: Dongfeng
authors.initials: D
authors.lastname: Tan
authors.forename: Jianmin
authors.initials: J
authors.lastname: Wang
authors.forename: Marilyn
authors.initials: M
authors.lastname: Intengan
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.forename: Sadir
authors.initials: S
authors.lastname: Alrawi
authors.forename: Peisha
authors.initials: P
authors.lastname: Yan
authors.forename: James C
authors.initials: JC
authors.lastname: Byrd