Polypoid endometriosis mimicking malignancy: a clinicopathological analysis of 28 cases and literature review

Abstract

Abstract Background Polypoid endometriosis (PEM) is rare benign tumors with morphological features resembling malignant tumors. We aimed to analyze the clinicopathological features and outcomes of patients with PEM, and compare them to cases of endometriosis with malignant transformation. Methods In total 28 PEM and 44 cases of endometriosis with malignant transformation were retrospectively analyzed. Data from each of the patients was collected including clinicopathological features, treatment, and outcomes for evaluation. Results In the PEM group patients were aged 30 to 63 years (mean, 40.7 years). The most common clinical symptoms were pelvic mass, irregular vaginal bleeding, and lower abdominal pain. The primary sites were ovary, posterior vaginal fornix, rectum, uterosacral ligament, and abdominal incision. The PEM tumors had a median maximum diameter of 5.3 cm (IQR, 3.1–7.9). The follow-up data in the PEM group showed that 23/27 patients survived without residual disease, 3/27 patients survived with residual endometriosis, 1/27 patient survived with endometriosis-malignant low-grade endometrial stromal sarcoma (ESS). Compared with patients in the endometriosis with malignant transformation group, there were statistically significant differences in age, menopause, dysmenorrhea, adenomyosis, cancer antigen 125 (CA125) levels, and tumor size. Conclusions PEM is a benign lesion and has a risk of malignant transformation. Patients with PEM were younger with a smaller tumor size and a higher CA125 level when compared to patients with endometriosis with malignant transformation, which provides important information for the correct diagnosis of PEM.