[938] Gastrointestinal Mucin Expression in Glandular Epithelia of the Uterus
G Axelson, A Nassar, T Giorgadze. East Tennessee State University, Johnson City, TN; Mayo Clinic, Rochester, MN; Wayne State University, Detroit, MI
Background: Aberrant expression of mucin (MUC) glycoproteins has been implicated in pathogenesis of various precancerous conditions and cancers. There is recent surge of interest to gastrointestinal (GI) phenotype of MUC expression in glandular lesions of the uterus. In this study we evaluated the utility of immunohistochemical (ICH) expression of MUC1 (panepithelial mucin), and GI mucins MUC2, MUC5AC, MUC6 (intestinal-type, gastric foveolar-type and pyloric gland-type mucins, respectively) in the differential diagnosis of glandular lesions of the uterus.
Design: IHC staining using monoclonal antibodies against MUC1, MUC2, MUC5AC, and MUC6 was performed on formalin-fixed paraffin-embedded archival tissue samples. These included: 4 normal endocervix, 5 tubal metaplasias, 5 microglandular hyperplasias, 9 endocervical polyps, 5 endometrial polyps, 6 endocervical adenocarcinomas (including 3 in situ adenocarcinomas), 5 normal endometrium, 4 endometrial hyperplasias (1 simple hyperplasia and 3 complex hyperplasias, including 1 with atypia), 9 endometrial adenocarcinomas. IHC staining was reported as negative, weakly positive, and strongly positive.
Results: The results are summarized in Table 1.
| Diagnoses/# of cases | MUC1 | MUC2 | MUC5AC | MUC6 |
| Normal endocervix, 4 | 4/4 | 0/4 | 3/4 | 0/4 |
| Tubal metaplasia, 5 | 5/5 | 0/5 | 0/5 | 0/5 |
| Microglandular hyperplasia, 5 | 5/5 | 2/5 | 5/5 | 3/5 |
| Endocervical polyp, 9 | 8/9 | 4/9 | 9/9 | 9/9 |
| Endocervical adenocarcinoma, 6 | 6/6 | 0/6 | 6/6 | 5/6 |
| Normal endometrium, 5 | 5/5 | 0/5 | 1/5 | 1/5 |
| Endometrial polyp, 5 | 5/5 | 2/5 | 2/5 | 3/5 |
| Endometrial hyperplasia, 4 | 4/4 | 1/4 | 4/4 | 3/4 |
| Endometrial adenocarcinoma, 9 | 9/9 | 2/9 | 7/9 | 6/9 |
Predominantly apical/membranous staining; Predominatly cytoplasmic stainingMUC expression in endometrial and endocervical polyps was most erratic. Contrary to previous reports, MUC2 was expressed in benign glandular epithelia of the uterine cervix and corpus. Only MUC1 was expressed in tubal metaplasias. MUC1 expression in endometrial hyperplasias and carcinomas was predominantly apical/membranous, whereas in endocervical adenocarcinomas it was predominantly cytoplasmic.
Conclusions: GI MUC expression is not uncommon in the uterine cervix and corpus. Significant overlap in GI MUC expression limits its utility in the differential diagnosis of benign and malignant glandular lesions of the uterus.
Category: Gynecologic
Monday, March 9, 2009 1:00 PM
Poster Session II # 145, Monday Afternoon