Mild forms of deep endometriosis may be detected only by palpation under an endometriotic lesion or by discovery of a palpable mass beneath visually normal peritoneum, most notably in the posterior cul-de-sac (Fig. 17.4) (200). At laparoscopy, deeply infiltrating endometriosis may have the appearance of minimal disease, resulting in an underestimation of disease severity (200). Reduced size of the cul-de-sac in women with deep endometriosis suggests that such lesions develop not in the rectovaginal septum but intraperitoneally and that burial of anterior rectal wall adhesions creates a false bottom, giving an erroneous impression of extraperitoneal origin (244).
Figure 17.1 Pelvic endometriosis.
The diagnosis of ovarian endometriosis is facilitated by careful inspection of all sides of both ovaries, which may be difficult when adhesions are present in more advanced stages of disease (Fig. 17.5). With superficial ovarian endometriosis, lesions can be both typical and subtle. Larger ovarian endometriotic cysts (i.e., endometriomas) usually are located on the anterior surface of the ovary and are associated with retraction, pigmentation, and adhesions to the posterior peritoneum. These ovarian endometriotic cysts often contain a thick, viscous dark brown ﬂuid (i.e., “chocolate ﬂuid”), composed of hemosiderin derived from previous intraovarian hemorrhage. Because this ﬂuid may be found in other conditions, such as in hemorrhagic corpus luteum cysts or neoplastic cysts, biopsy and preferably removal of the ovarian cyst for histologic confirmation are necessary for the diagnosis in the revised endometriosis classification of the American Society for Reproductive Medicine (ASRM). If that is not possible, the presence of an ovarian endometriotic cyst should be confirmed by the following features: cyst diameter of less than 12 cm, adhesion to pelvic sidewall or broad ligament, endometriosis on surface of ovary, and tarry, thick, chocolate-colored ﬂuid content (245). Ovarian endometriosis appears to be a marker for more extensive pelvic and intestinal disease. Exclusive ovarian disease is found in only 1% of endometriosis patients, with the remaining patients having extensive pelvic or intestinal endometriosis (246).
Figure 17.2 Typical and subtle endometriotic lesions on peritoneum. A: Typical black-puckered lesions with hypervascularization and orange polypoid vesicles. B: Red polypoid lesions with hypervascularization. (Photographs from Dr. Christel Meuleman, Leuven University Fertility Center, Leuven University Hospitals, Leuven, Belgium.)
Figure 17.3 Ovarian endometriosis. (Photographs from Dr. Christel Meuleman, Leuven University Fertility Center, Leuven University Hospitals, Leuven, Belgium.) A: Superficial ovarian endometriosis. B: Superficial ovarian endometriosis and endometrioma—laparoscopic image prior to adhesiolysis.
Figure 17.3 (continued) C: Laparoscopic image of uterus and right ovary with dark endometrioma. D: Ovarian endometriotic cystectomy
Histologic Confirmation Positive histology confirms the diagnosis of endometriosis; negative histology does not exclude it (1). Whether histology should be obtained when peritoneal disease alone is present is controversial; visual inspection is usually adequate but histological confirmation of at least one lesion is ideal (1). In cases of ovarian endometrioma (>4 cm in diameter) and in deeply infiltrating disease, histology is recommended to exclude rare instances of malignancy (1).
Figure 17.3 (continued) E: Ovarian endometriotic cystectomy.