Functional endometrial polyps in infertile asymptomatic patients: a possible evolution of vascular changes secondary to endometritis.

OBJECTIVE: Functional polyps and chronic endometritis are among the most common abnormalities seen in the endometrium of patients with implantation failures and recurrent miscarriages. In this study we describe morphological vascular changes in endometrial samples from asymptomatic infertile patients and their association with chronic endometritis and polyp.

STUDY DESIGN: We selected 435 asymptomatic infertility patients submitted to office-based diagnostic hysteroscopy and endometrial biopsy. We described vascular changes and searched for histologic signs of endometritis and functional polyps in the endometrial samples. We explored the associations between these conditions.

RESULTS: Signs of endometritis, vascular changes and polyps were identified in 176 (40.5%), 168 (38.6%) and 102 (23.4%) cases, respectively. There was a significant association between endometritis and vascular changes. The more frequent vascular alteration (70%) was the hyaline thickening of vessels, a morphological pattern very similar to the thick-walled vessels of polyps. Polyps were associated with endometritis in 28 (27.4%) cases and with other vascular changes besides the vascular stalk in 14 (13.7%). All the polyps with vascular changes had histologic evidence of endometritis. There was a significant association between inflammatory phenomena and vascular changes, even among cases of polyps.

CONCLUSIONS: Endometrial samples from infertile patients present a broad spectrum of vascular changes, most of them associated with endometritis. This association is also identified in functional polyps. Our results suggest that these alterations may be etiologically related. It is possible that the vessel axis of functional polyps actually may originate from the evolution of the vascular changes associated with endometritis. This would place functional polyps among the spectrum of inflammatory endometrial diseases.