Comparison of the distinctive pathological features of and p16 and c-Kitexpression levels in benign and malignant endometrial polyps.

Abstract

Histopathological examination is crucial for the effective management of endometrial polyps. Immunohistochemical markers such as p16 and c-Kit may facilitate the differential diagnoses of benign and malignant polyps. The aim of the present study was to explore the expression levels of c-Kit (CD117) and p16 in endometrial polyps of postmenopausal women. Twenty-five hysterectomy specimens with malignant endometrial polyps and hysterectomy or polypectomy specimens featuring 55 benign polyps were studied. The polyps were immunohistochemically stained for p16 and c-Kit, and differences in the expression levels of these proteins in the glandular and stromal components of benign polyps and the benign regions of the malignant polyps were assessed by using Fisher's exact test. The glandular components of malignant polyps exhibited significantly more intense p16 immunostaining than did benign polyps. Most immunoreactive cells were glandular cells exhibiting tubal metaplasia. The stromal components of either type of polyp did not differ in terms of p16 immunostaining. The extent of c-Kit immunostaining in benign and malignant polyps was similar. The extensive tubal metaplasia in and the p16 immunoreactivity of the glandular components of malignant polyps may be useful to distinguish such polyps from benign polyps.