Possible Inflammatory Origin of Endometrial Polyps

Objective: Endometrial polyps are the most frequent gynaecological pathology. The growth of endometrial polyps (EP) is though to be related to abnormal hormonal signalling; however, endometrial polyps and chronic endometritis (CE) frequently coexist. The aim of this study was to evaluate the expression of VEGF and TGFβ isoforms in the epithelium and stromal cells from endometrial polyps (P) and in the endometrium from the contralateral side of the cavity in women with or without signs of CE.

Design: Case-control study.

Setting: Academic Centre.

Patients: Forty-six women referring for hysteroscopy were divided into 2 groups on the basis of hysteroscopic findings. Group A with endometrial polyps and normal controlateral endometrium, and Group B with polyps and presence of signs of CE.

Interventions: Office hysteroscopy, polypectomy and endometrial biopsies.

Main Outcome Measures: The immuno-histochemical evaluation of VEGF, TGFβ1, TGFβ2 and TGFβ3 expressions.

Results: VGEF, TGFβ1 and TGFβ2 were expressed more in the glandular epithelium than in stromal cells. VGEF and TGFβ1 levels in women with CE were higher compared to women without CE and in polyps compared to the contralateral endometrium. On the contrary, in the stroma the expressions of TGFβ1 and TGFβ2 showed no inter-group differences. However, TGFβ3 was significantly overexpressed in polyps from group B but not from group A and in particular in the stromal cells with “spindle cell” characteristics.

Conclusions: The different expressions of growth factors may imply the existence of two different kinds of endometrial polyps, one hormone dependent and the other of inflammatory nature. The different nature may result in different symptoms, risk of relapse, reproductive and oncologic consequences.

Keywords: Endometrial polyps, inflammation, chronic endometritis, VEGF, TGFβ.