Hysterosalpingography is not recommended as a diagnostic test for endometriosis, although the presence of filling defects (presence of hypertrophic or polypoid endometrium) has a significant positive correlation with endometriosis (positive and negative predictive values of 84% and 75%, respectively) (207).
Imaging to Assess Intestinal and Urologic Involvement
If there is clinical evidence of deeply infiltrating endometriosis, ureteral, bladder, and bowel involvement should be assessed. Ureteral involvement may be asymptomatic in up to 50% of patients with deeply infiltrative endometriosis (208). Consideration should be given to performing ultrasound (transrectal, transvaginal or renal), a CT urogram, or an MRI. A barium enema study might be useful, depending on the individual circumstances, to map the extent of disease present, which may be multifocal (1). There is no proof that one technique is superior to another; it is recommended that the technique that is most familiar to the radiologist involved be used.
Blood and Other Tests There is no specific blood test for the diagnosis of endometriosis. A general endometriosis screening test may be neither appropriate (risk for overdiagnosis) nor feasible. A blood test with a high sensitivity would be useful if that would identify women with symptomatic endometriosis (pelvic pain, infertility) that is not detectable by ultrasound imaging (209). This would include all cases of minimal to mild endometriosis and those cases of moderate to severe endometriosis without detectable ovarian endometriotic cysts or nodules (210). These are patients who could benefit from laparoscopic surgery to reduce endometriosis-associated pain and infertility or to diagnose and treat other pelvic causes of pelvic pain or infertility, like pelvic adhesions. From that perspective, a lower specificity would be acceptable because the main goal of such a test would be to rule in all women with potential endometriosis or other pelvic disease who might benefit from surgery (211).
CA125 Levels of CA125, a glycoprotein from coelomic epithelium and common to most nonmucinous epithelial ovarian carcinomas, are significantly higher in women with moderate or severe endometriosis and normal in women with minimal or mild disease (212,213). It is presumed that endometriosis lesions produce peritoneal irritation and inﬂammation and this leads to an increased shedding of CA125 (213). During menstruation, an increase in CA125 levels was shown in women with and without endometriosis (214–218). Other studies did not find an increase during menses, or found an increase only with moderate to severe endometriosis (219–222). The levels of CA125 vary widely: in patients without endometriosis (8–22 U/mL in the nonmenstrual phase), in those with minimal to mild endometriosis (14–31 U/mL in the nonmenstrual phase), and in those with moderate to severe disease (13–95 U/mL in the non-menstrual phase). Compared with laparoscopy, measurement of serum CA125 levels has no value as a diagnostic tool (223).