QUANTITATIVE IMAGE-ANALYSIS OF MIB-1 REACTIVITY IN INFLAMMATORY, HYPERPLASTIC, AND NEOPLASTIC ENDOCERVICAL LESIONS

The diagnosis of endocervical neoplasia can be difficult as it is some times mimicked by proliferative or reactive glands. MIB-1 is a prolife ration marker that can aid in the diagnosis of squamous intraepithelia l lesions (SIL) of the cervix and vulva, but its potential value in th e diagnosis of endocervical lesions has not been fully explored. Ten f ormalin-fixed, paraffin-embedded cases of each of the following were o btained: morphologically normal endocervical glands from patients with cervical SIL, endocervicitis, microglandular hyperplasia (MGH), and e ndocervical adenocarcinomas (eight in situ, two invasive). Microwave u nmasking of antigens was performed prior to immunohistochemical staini ng for MIB-1 using the avidin/biotin peroxidase method. Labeling index es were calculated for 34 specimens (10 adenocarcinoma, 8 each of the other diagnoses) using image analysis (Samba 4000). There was diffuse MIB-1 reactivity in adenocarcinoma (labeling index 57-96%, mean 80%), minimal focal reactivity in normal glands underlying SIL (labeling ind ex 0.8-4.3%, mean 2.4%), moderate spotty reactivity in MGH (labeling i ndex 2.9-18.4%, mean 8.5%), and minimal to focally diffuse reactivity in endocervicitis (labeling index 1.0-13.3%, mean 5.7%). These data in dicate that the percentage and distribution of MIB-1-reactive endocerv ical cells can be of diagnostic utility in distinguishing neoplastic g lands from those of endocervicitis and MGH.