Gastric-type adenocarcinoma (GA) is an aggressive subtype of cancer of the uterine cervix. Several immunohistochemical markers for gastric mucins, such as mucin 6 (MUC6) and N-acetylglucosamine α1 → 4galactose → R (αGlcNAc-R), which is recognized by HIK1083 antibody, have been introduced for diagnosis of GA and lobular endocervical glandular hyperplasia (LEGH). However, MUC6 is also expressed in normal endocervical glands and HIK1083 antibody has limited availability. Trefoil factor family 2 protein (TFF2) is secreted by gastric, but not normal endocervical glands. Here, we evaluated TFF2 immunostaining for detection of a gastric immunophenotype in endocervical glandular lesions. We compared TFF2, αGlcNAc-R, and MUC6 expression in 103 endocervical glandular lesions: LEGH (n = 23), adenocarcinoma in situ/microinvasive adenocarcinoma (AIS-MIA) (n = 29), and invasive adenocarcinoma (usual type [UA], n = 26; GA, n = 11; intestinal type [IA], n = 2; signet ring cell type [Sig], n = 2; and mucinous adenocarcinoma not otherwise specified [NOS], n = 10). TFF2 and αGlcNAc-R expression was completely concordant in each subtype: LEGH (100%), AIS-MIA (44.8%), UA (26.9%), GA (90.9%), IA (100%), Sig (0%), and NOS (20%). TFF2 staining scores were significantly correlated with those of αGlcNAc-R in these lesions. TFF2 and αGlcNAc-R immunoreactivity was present in cytoplasmic mucins and luminal secretions. TFF2 and αGlcNAc-R were not expressed in the normal endocervical glands. MUC6 was frequently expressed in normal endocervical glands and endocervical glandular lesions. Endocervical adenocarcinomas sometimes stained only for MUC6. TFF2 is a promising immunohistochemical marker and its identification in uterine cervical secretion is a potentially useful diagnostic test for endocervical glandular lesions with gastric differentiation.
Keywords: Cervical adenocarcinoma; Gastric mucin; Gastric type; LEGH; TFF2; αGlcNAc.