Basement membrane pattern in hyperplastic and neoplastic lesions of the endometrium the value of immunoperoxidase stain in the identification of borderline lesions

ABSTRACT

Atypical adenomatous hyperplasia and well-differentiated endometrial adenocarcinoma are sometimes difficult to diagnose on histology alone. It was therefore decided to study the basement membrane pattern of the hyperplastic and neoplastic endometrium, with the help of immunoper-oxidase stain, using specific antibody against the laminin component of the basement membrane. For this purpose 25 blocks each of normal endometrium in various phases of menstrual cycle, cystic hyperplasia, adenomatous hyperplasia and adenocarcinoma were selected for study. The staining was done with Histoset immunoperoxidase staining kit from E.Y. Laboratories. The procedure recommended by the suppliers was adopted. It was based on the methodology described by Sternberger. The stain demonstrated small breaks in a few glands in 4 cases of atypical adenomatous hyperplasia, well-defined breaks in 10 cases of non-invasive or micro-invasive carcinomas, gland breaks and fragmentation in 15 cases of frankly invasive adenocarcinoma. An intact basement membrane was seen in the normal endometrium during the various phases of the menstrual cycle and benign hyperplastic endometrium. Thus this technique helped in the differentiation of benign hyperplastic lesions, atypical adenomatous hyperplasia, and well-differentiated non-invasive or micro-invasive adenocarcinoma