microscopic Endo

Microscopic Endometriosis

A staggering 35% of laparoscopies done on patients with pelvic pain are considered "negative," giving no indication of any physical cause(s) for pain.⁽¹⁾ If you've had a negative laparoscopy, does that mean you don't have Endometriosis? Not necessarily. You may be one of the many patients who have "microscopic" disease. Negative laparoscopy results do not always mean that patients have no Endometriosis.⁽²⁾

"Microscopic" simply means "too small to be seen clearly without the use of a microscope." Some specialists debate that microscopic disease even really exists; questioning rather if it is just Endometriosis that is unrecognized by practitioners who look only for visible or "classic" lesions, or who do not use the proper magnifying equipment during surgery. One Endometriosis specialist has even stated, "Endometriosis is not microscopic or invisible. Surgeons can see individual glands if they know what to look for."⁽³⁾

Getting a negative diagnosis can leave a patient feeling distraught. Not only has her pain been unresolved, but she has not even been afforded the benefit of knowing what caused the pain in the first place. Her symptoms, which may not have been taken seriously to begin with, may now be questioned yet again by her practitioner. Could her pain just be in her head? More likely than not, no...the pain is in her pelvis.

Even if no Endometriosis is seen during laparoscopy, the surgeon should still obtain samples of tissue for biopsy. Pathology results often show evidence of disease in otherwise normal-appearing areas. For example, in one study, 100 patients undergoing laparoscopy for infertility ('group 1'), chronic pelvic pain ('group 2') and tubal sterilization ('group 3') had biopsies taken from areas of what appeared to be normal peritoneum. The results? 26 patients in group 1, 8 patients in group 2 and 13 patients in group 3 had evidence of pelvic Endometriosis. Authors concluded that a high prevalence of Endometriosis - including the microscopic form - exists in both fertile and infertile women; those with chronic pelvic pain and those who are asymptomatic.⁽⁴⁾

In another review of case histories, surgeons discovered that 1 patient demonstrated a 1-mm lesion of Endometriosis beneath a "visually normal peritoneum," and 2 other patients had surface zones of possible endometrial stroma, thereby supporting the existence of unrecognized subperitoneal and microscopic surface Endometriosis.⁽⁵⁾

Ultrasounds and MRIs may be of some use in diagnosing Endometriosis, particularly in women with large Endometriomas. However, microscopic or small implants and adhesions are not well evaluated radiologically⁽⁶⁾; therefore, laparoscopy remains the gold standard for diagnosis and staging.

Pain Mapping (Patient Assisted Laparoscopy) can be very helpful in detecting microscopic disease and pinpointing other causes of pelvic pain in cases where no obvious reason appears. In one study, 100 patients with pelvic pain were assessed by PAL to determine the cause of their chronic pelvic pain. Out of the 100 patients, 12 could not be assessed due to reaction to the carbon dioxide gas, inadequate visualization due to adhesions, and failure to enter the peritoneum. Of the remaining 88 patients, 61 had Endometriosis. Other causes for pain were adhesions, hernias, occult bowel cancer, a pseudostone from a previous cholecystectomy, pain resulting from the use of staples in a previous hysterectomy, and Chrohn's disease. Only 2 patients exhibited no interabdominal cause for their symptoms. Authors evidenced through this study that PAL was able to decrease the negative laparoscopy rate (35%) to less than 3%.⁽⁷⁾

Other researchers believe that diagnostic tests during a laparoscopy can determine the clinical sensitivity of pelvic surfaces and thereby indicate Endometriosis in areas that do not show evidence of disease. One such diagnostic method is called the "Bubble Test." This is an interesting approach involving the irrigation of the pelvic area with solution (i.e. saline or lactated Ringer's), followed by standard laparoscopic aspiration, and then observing for "an excessive soap-like bubbling phenomenon in association with Endometriosis." In one study, the "Bubble Test" was 100% sensitive and 88% specific for the confirmed diagnosis of Endometriosis, even in the absence of obviously visible disease.⁽⁸⁾

Still others feel that microscopic Endometriosis may be detected through an immunological method. Because the disease has been linked to alterations in immune function, several different antibody detection systems can be used when there is an unclear surgical diagnosis.⁽⁹⁾

In addition to pain without a visual cause, microscopic Endometriosis can also be a factor in persistent pelvic pain following hysterectomy. While it is known that a hysterectomy is not a cure for Endometriosis, some patients find their post-hysterectomy pain and symptoms are discounted by their physician when repeat laparoscopy does not "show" any disease. Pathology reports, on the other hand, may tell a different story and clearly define the presence of Endometriosis. In one 6 year long study, Endometriosis was shown to occur in several of the patients following their hysterectomy. Authors noted that "small, even microscopic, fragments...can proliferate and ultimately result in pelvic pain and masses," even following removal of the reproductive organs.⁽¹⁰⁾

Microscopic disease may also be overlooked in the presence of other pathology. In one such instance, a patient's symptoms were initially blamed on her rare case of ovarian pregnancy. It was later discovered through histology that the patient also had microscopic Endometriosis.⁽¹¹⁾To further complicate matters, microscopic disease can masquerade as other ailments. In a report detailing 6 cases of appendiceal Endometriosis, it was noted that Endometriosis "rarely appears visually" on the appendix and that many of the cases presented as "acute appendicitis." Pathological examinations of the removed appendices showed that the problem was actually Endometriosis.⁽¹²⁾

Finding a specialist, who is trained to recognize implants in all forms, is imperative in order to obtain effective treatment of Endometriosis. If surgery fails to relieve your symptoms and does not "show" any reason for your pain, talk to your surgeon about the possible presence of microscopic disease. Most of all, request before surgery that biopsies be performed on random tissue samples taken during the procedure. Endometriosis could be hiding in plain sight.

For more information:

Education & Support:
Endometriosis Research Center

Photos and Histology Stains of Microscopic Endometriosis:
Département de Gynécologie et d'Obstétrique/Hôpitaux Universitaires de Genève

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References:
1) & 7) "Effect on negative laparoscopy rate in chronic pelvic pain patients using patient assisted laparoscopy," J Soc Laparoendosc Surg 1997 Oct-Dec;1(4):319-21. Demco, LA.
2) "Endometriosis and pain," Clin Obstet Gynecol 1999 Sep;42(3):664-86. Martin DC, Ling FW, University of Tennessee, Memphis.
3) David B. Redwine, M.D., Director, St. Charles Medical Center Endometriosis Treatment Program.
4) "Visible and non-visible endometriosis at laparoscopy in fertile and infertile women and in patients with chronic pelvic pain: a prospective study," Hum Reprod 1996 Feb. 11(2):387-91. Balasch J, Creus M, Fabregues F, Carmona F, Ordi J, Martinez-Roman S, Vanrell JA, Dept of ObGy, Faculty of Medicine, University of Barcelona, Hospital Clinic i Provincial, Spain.
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8) "The bubble test: a new tool to improve the diagnosis of endometriosis," Hum Reprod 1995 Apr;10(4):923-6. Gleicher N, Karande V, Rabin D, Dudkiewicz A, Pratt D, Center for Human Reproduction, Chicago, IL 60610.
9) "Endometrial Autoantibodies and Endometriosis," by Gary W. Randall, Ph.D., HCLD, Mid-South Fertility Institute.
10) "Disseminated leiomyomatosis and endometriosis following laparoscopic supracervical hysterectomy," Obstet Gynecol 2000 Apr 1;95(4 Suppl 1):S35. Kung R, Lie KI, Women's College Hospital, University of Toronto, Ontario, Canada.
11) "Ovarian pregnancy associated with microscopic decidualized endometriosis of the ovary: report of a case," J Obstet Gynaecol Res 1998 Feb;24(1):45-8. Toki T, Obinata M, Nakayama K, Oguchi O, Fujii S, Dept. of ObGyn, Shinshu University of Medicine, Matsumoto, Japan.
12) "Appendiceal Endometriosis," Ginekol Pol 1997 May;68(5A):277-9. Gwozdz AZ, II Kinika Ginekologii i Poloznictwa Obserwacyjnego Instytutu Ginekologii i Poloznictwa Akademii Medycznej w Lodzi, Poland.