Deep endometriosis: a consequence of infiltration or retraction or possibly adenomyosis externa?

OBJECTIVE: To analyze the incidence and occurrence of subtypes of deep endometriosis.
DESIGN: Deep endometriotic lesions (> 5 mm) were retrospectively analyzed, using our data base and slides taken systematically during surgery.
SETTING: University Hospital Gasthuisberg (University of Leuven) which is a referral center for infertility and endoscopic surgery. PATIENTS: All women with deep endometriosis (n = 136) were selected from a consecutive series of 1,252 laparoscopies for infertility, pain, or both. INTERVENTIONS AND MAIN OUTCOME MEASUREMENTS: Deep endometriosis was excised by CO2 laser and the depth of infiltration and the pelvic area measured. As part of an ongoing study, most lesions were photographed.
RESULTS: Deep endometriosis is suggested to contain three subgroups. Type I is conical shaped and suggested to be formed by infiltration. Type II is deeply located and covered by extensive adhesions and probably formed by retraction. Type III is a spherical nodule with its largest dimension under the peritoneum. Types I, II, and III are found in 4.1%, 0.8%, and 0.9% of women with infertility (n = 759) and in 10.4%, 3.2%, and 3.2% of women with pelvic pain (n = 374). Types I, II, and III are most frequently found in the revised American Fertility Society classes II, III to IV, and I, respectively.
CONCLUSIONS: Three subtypes of deep endometriosis can be distinguished. Type III, which is a spherical nodule located in the recto vaginal septum is the most severe and largest lesion. This is, however, easily missed clinically because these lesions are generally scored as revised American Fertility Society class I.