Histologic analysis of endometriomas: what the surgeon needs to know

To evaluate by thorough pathologic analysis the histologic features of the endometrioma wall excised at laparoscopy.

Prospective series of consecutive patients.

Tertiary care, university hospital.

Fifty-nine patients with ovarian endometriomas. A total of 70 cysts were examined.

Patients underwent operative laparoscopy with the stripping technique for excision of the ovarian endometrioma.

A thorough histologic examination was performed on the entire cyst wall specimen.

Histologic examination confirmed the endometriotic nature of the cyst in 100% of the cases. The inner wall of the endometrioma was covered by endometriotic tissue on 60% of the surface. The mean cyst wall thickness was 1.4 mm. The mean value of maximal depth of endometriosis penetration in the endometrioma wall was 0.6 mm. In 99% of the cases the maximal penetration of the endometriotic tissue was <1.5 mm.

In the present study, we demonstrate that the endometrioma wall contains endometriotic tissue in 100% of the cases. However, the endometriotic tissue may cover the inner cyst wall for a surface that varies between 10% and 98% of the entire wall (median value 60%). This tissue may reach a depth of 2 mm, but for most of the surface it does not penetrate >1.5 mm. These histologic data may help the gynecologic laparoscopist select the surgical approach that maximally preserves healthy ovarian tissue.