Clinical Characteristics of Endometriosis

Robert G. Good, M.D.
Associate Clinical Professor, Department of Obstetrics and Gynecology, U.C.L.A.

Endometriosis, Aspects and Proceedings of a Symposium
Saint John's Hospital and Health Center, Santa Monica, California
Editor: J.J. Marik

In reviewing the case histories of some 80 endometriosis patients over the past three years, one could observe that as a group, these patients could generally be described as intelligent; in the upper socioeconomic groups; hard, striving women, who may tend to delay both marriage and childbearing.

Over twenty years ago, at the Massachusetts General Hospital, Joseph Meggs noted that endometriosis was common in patients of the upper socioeconomic group. He observed that some 25% of patients coming to surgery from the private sector of the community had some evidence of endometriosis, while in the less affluent clinic population, only 5% of patients had endometriosis.

One of the reasons for the recent apparent increase in the incidence of endometriosis relates to a delay in the childbearing age. In 1955 the mean age of the patient having her first baby at St. John's Hospital was 23 years of age; in 1965 it was 25 years of age; and in 1975 this mean age had increased to 27. This is particularly interesting, as the mean age at the time of diagnosis of endometriosis in our 80 patients was 28, and 70% were from 21 to 25 years of age, so that women today are in fact waiting to have their first child until virtually the same age at which endometriosis is most likely to occur.

It is also very interesting to note the relationship between endometriosis and conception. In our 80 patients, there were 15 who had one or more pregnancies accounting for a term pregnancy rate of 18.7%. Furthermore, 13 of these 15 pregnancies occurred in those patients whose endometriosis was not diagnosed until after 31 years of age. It therefore becomes apparent that the patients who became pregnant did so in an interval of time several years prior to the development of endometriosis. In our average patient, a child was delivered about ten years before endometriosis was diagnosed.
As a result, most of these patients do very poorly in terms of acquiring a term pregnancy, with only two out of the 80 patients delivering a term infant within a year of the diagnosis of endometriosis. Clearly, endometriosis is a dramatic and important cause of infertility.

With regard to the primary presenting symptoms of endometriosis, patients may report pain, infertility and bleeding, but far and away the most outstanding presenting characteristic of endometriosis is pain. This pain may take three forms: secondary or acquired dysmenorrhea; deep dyspareunia; or painful bowel movements during a time of menstrual periods.

A much smaller number of our patients-only 6%-presented with a mass, which was determined to be either an endometrioma or associated uterine fibroids. With regard to fibroids and their association with endometriosis, it should be noted that in this series of 80 patients some 15 percent of the patients had coexisting uterine leiomyomata. Most of these patients were older than 35.

It is of interest that three of our 80 patients presented with bowel obstructions; two of these had small-bowel obstructions with the obstructing area of endometriosis occupying the ileum. One 45-year-old patient presented with a large-bowel obstruction and an annular-appearing lesion of the rectosigmoid, which initially was thought to be a carcinoma of the rectosigmoid but was in fact a constricting area of endometriosis.

Many of these patients also complain of metrorrhagia, typically spotting prior to the onset of the menstrual period; another characteristic lead-in pattern sometimes seen is quite erratic periods.
Although the diagnosis of endometriosis can be made in a variety of ways, by being very much aware of endometriosis we have been able to make this diagnosis on the basis of physical examination in about 40% of the patients. All of these patients eventually have had endometriosis demonstrated on the basis of laparotomy or laparoscopy.

The classic lesions on examination are nodularity of the uterosacral ligaments and of the cul-de-sac area. It is also interesting to note that the left uterosacral ligament seems to be more often and more extensively involved in endometriosis than the right. Thirty-two percent of our patients were diagnosed by laparotomy. These patients either had endometriomas greater than 5 or 6 centimeters in size, or a coexisting uterine leiomyoma. The approximately 25% of patients where the diagnosis could not be made from physical examination are the most difficult diagnostic cases. But, of course, these are the patients whom we have the greatest opportunity of benefiting, both in reproductive function and comfort. In this regard, I would emphasize that every good infertility evaluation uses laparoscopy as an integral part of that study, and that the laparoscope is absolutely indispensable in the evaluation of pelvic pain.

Another very interesting pattern in these 80 endometriosis patients was seen in terms of their contraceptive techniques. In spite of the fact that virtually all of these women with endometriosis were sexually active, a total of 46% used no contraception at all. This may well be because time had shown they would not become pregnant in any case. Of the balance, 26% used a diaphragm (a large percentage for my practice). And it is most impressive to note that only 6% of these patients who ultimately had endometriosis diagnosed used oral contraceptives. This compared to 64% of a comparably matched group of nonendometriosis patients in our practice.

In view of this finding, we would suggest that there may well be a factor in oral contraceptives that can prevent endometriosis. This data is strongly suggestive that administration of oral contraceptives is in fact good prophylactic medicine in the prevention of endometriosis, especially at a time when more and more women are progressively delaying the birth of their first child.

To summarize, the following profile can be drawn of the "typical" patient with endometriosis. This patient is typically in the upper socioeconomic group, 20 to 35 years of age, and has a very low fertility rate. If a pregnancy has been achieved and a baby delivered, in all probability more than five years have elapsed before the demonstration and diagnosis of endometriosis. Additionally, these patients complain of bleeding, pain and infertility, symptoms which, taken as a group, are strongly suggestive of endometriosis. Finally, and very importantly, as a group these women have depended either on no contraception or on ovulatory techniques of contraception distinct from the "pill."

Unfortunately, the diagnosis of endometriosis does not lend itself well to a single laboratory test. Equally unfortunate is the fact that the patients with endometriosis we want most to identify - the early ones - are precisely those who often have no physical findings. Therefore, the characteristics of the "typical" endometriosis patients are very important to bear in mind. In this way we will be able to identify the early cases, and accordingly bring about therapy that is a good deal more successful.

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