Endometriosis and the Appendix - Incidence and Pathologic Analysis

Endometriosis is the presence of endometrial and stromal glands at extrauterine sites. One of the extrauterine sites that may be involved is the GI tract. The extent of bowel involvement can range from an incidental spot on the serosa to ectopic endometrium causing a bowel obstruction. The rate at which the bowel is involved ranges from 3-34%, as noted by Gustofson in a literature review published in Fertility and Sterility. The symptomatology of GI endometriosis can be vast. Presenting as cyclic or chronic pelvic pain, right lower quadrant pain, melena, GI upset/pain, and as serious as intussusception and appendicitis.

The incidence with which endometriosis is identified in the appendix potentially causing the complications that were noted, is reported as a wide range, 1-22%. The low of 1% is reported in two separate studies. The first, by Harper and Soules, published in the International Journal of Gynecology and Obstetrics, and the second, by Weed and Ray, in Obstetrics and Gynecology. The highest rate of 22% was reported by Berker and colleagues in the Journal of Minimally Invasive Gynecology. Noting the possibility of greater than 20% of individuals with endometriosis having appendiceal involvement, incidental appendectomy may be of benefit.

The American College of Obstetrics and Gynecology (ACOG) released a Committee Opinion on incidental appendectomy that was reaffirmed in 2012. These are the guidelines that are followed by gynecologists today. ACOG notes that women 35years of age and younger benefit the most from elective coincidental appendectomy. Others who may be of significant benefit are those patients with a complicated differential, those in who chemotherapy is anticipated, and those who are expected to have extensive post-op adhesions.

ACOG goes on to note that the decision to perform an appendectomy at the time of a gynecologic procedure should be based on individual scenarios after the risks and benefits are discussed with the patient. The procedure has a low risk of morbidity, and if there is reasonable probability the benefits outweigh the risks, based on age or history, elective coincidental appendectomy during primary gynecologic procedure may be appropriate.

Considering the variation seen in publications, the rate of diagnosis that the surgeon may find may be broad. The reason for this variation, though, is under speculation. Although, it is most likely multifactorial, the method with which the specimen is analyzed may play a role. In all of the methods sections in the above mentioned research papers and others regarding this topic, description of the technique used for pathologic analysis was not available. Here at Penn State Hershey Medical Center, a 3 slice method is employed. A cut is made at the proximal and distal end, and a third cut in the center. If this method is modified to include more cuts, the hypothesis is that endometriosis of the appendix will be diagnosed at a higher rate. Appendix specimens will be collected as indicated, following ACOG recommendations. After removal of the appendix patient's will be consented to allow the second pathologic analysis. Time frame for collection and second analysis will be approximately 12 months, the anticipated time to obtain 100 specimens.