Progression of Deep Infiltrating Rectosigmoid Endometriotic Nodules

Antoine Netter; Perrine d'Avout-Fourdinier; Aubert Agostini; Isabella Chanavaz-Lacheray; Marta Lampika; Marilena Farella; Clotilde Hennetier; Horace Roman


Hum Reprod. 2019;34(11):2144-2152. 

In This Article

Abstract and Introduction


Study Question: What is the risk of progression of deep endometriotic nodules infiltrating the rectosigmoid?

Summary Answer: There is a risk of progression of deep endometriotic nodules infiltrating the rectosigmoid, particularly in menstruating women.

What is Known Already: Currently, there is a lack of acceptance in the literature on the probability that deeply infiltrating rectosigmoid endometriotic nodules progress in size.

Study Design, Size, Duration: We conducted a monocentric case–control study between September 2016 and March 2018 at Rouen University Hospital. We enrolled 43 patients who were referred to our tertiary referral centre with deep endometriosis infiltrating the rectosigmoid, who had undergone two MRI examinations at least 12 months apart and had not undergone surgical treatment of rectosigmoid endometriosis during this interval.

Participants/Materials, Setting, Methods: MRI images were reinterpreted by a senior radiologist with experience and expertise in endometriosis, who measured the length and thickness of deep infiltrating colorectal lesions. Intra- and inter-observer reliability were tested on 30 randomly selected cases. We defined 'progression' of a nodule as an increase of ≥20% in length or in thickness and 'regression' of a lesion as a decrease of ≥20% in length or in thickness between two MRIs. Any nodule for which the variation in length and thickness was <20% was considered as 'stable'. Patients were divided into three groups based on evidence of progression, regression or stability of deep endometriotic nodules between their two MRI examinations. The total length of any period of amenorrhoea between the two MRI examinations, due to pregnancy, breastfeeding or hormonal treatment, was recorded. The total proportion of the time between MRIs where amenorrhoea occurred was compared between groups.

Main Results and the Role of Chance: Eighty-six patients underwent at least two MRIs for deep endometriosis infiltrating the sigmoid or rectum between September 2016 and March 2018. Of these, we excluded 10 patients with an interval of <12 months between MRIs, 10 patients who underwent surgery between MRIs, 17 patients for whom at least 1 MRI was considered to be of poor quality and 6 patients for whom no deep colorectal lesion was found on repeat review of either MRI. This resulted in a total of 43 patients eligible for enrolment in the final analysis. Mean time (SD) between MRIs was 38.3 (22.1) months. About 60.5% of patients demonstrated stability of their colorectal lesions between the two MRIs, 27.9% of patients met the criteria for 'progression' of lesions and 11.6% met the criteria for 'regression' of lesions. There was no significant difference in time interval between MRIs for the three groups (P = 0.76). Median duration of amenorrhoea was significantly lower in women with progression of lesions (7.5 months) when compared to those with stability of lesions (8.5 months) or regression of lesions (21 months) (P < 0.001). Median duration of amenorrhoea (expressed as percentage of total time between two MRIs) was also found to be significantly lower in the group demonstrating progression (15.1%) when compared to the group demonstrating stability (19.2%) and the group demonstrating regression (94.1%; P = 0.006). Progression of rectosigmoid nodules was observed in 34% of patients without continuous amenorrhoea, in 39% who had never had amenorrhoea and in no patients with continuous amenorrhoea.

Limitations, Reasons for Caution: Due to a lack of universally accepted criteria for defining the progression or regression of deep endometriotic nodules on MRI, the values used in our study may be disputed. Due to the retrospective design of the study, there may be heterogeneity of interval between MRIs, MRI techniques used, reason for amenorrhoea and duration of amenorrhoea. The mean inter-MRI interval was of short duration and varied between patients. Our findings are reported for only deep endometriosis infiltrating the rectosigmoid and cannot be extrapolated, without caution, to nodules of other locations.

Wider Implications of the Findings: Patients with deeply infiltrating rectosigmoid endometriotic nodules, for which surgical management has not been performed, should undergo surveillance to allow detection of growth of nodules, particularly when continuous amenorrhoea has not been achieved. This recommendation is of importance to young patients with rectosigmoid nodules who wish to conceive, in whom first line ART is planned. There is a very low risk of progression of deep endometriotic nodules infiltrating the rectosigmoid in women with amenorrhoea induced by medical therapy, lactation or pregnancy.

Study Funding/Competing Interest(S): No funding was received for this study. The authors declare no competing interests related to this study.


Although endometriosis is common among women of reproductive age, its natural history is still debated (Giudice, 2010; Gordts et al., 2017). Hormonal treatments used either for treatment of infertility or for contraception may interfere with the natural evolution of the disease (Fedele et al., 2000), which makes the assessment of progression of endometriotic lesions over time challenging. Thus, data on this matter are scarce in the scientific literature: only one prospective study exists. In this study, asymptomatic and untreated women with deep endometriotic lesions infiltrating the rectum were followed up for a median time of 6 years, and the study concluded that asymptomatic deep nodules are unlikely to progress (Fedele et al., 2004). Other arguments against the progression of endometriosis are based only on retrospective studies conducted on indirect outcomes or on biological data (Savaris et al., 2014; Zhang et al., 2016a,b; González-Foruria et al., 2017). In addition, there is also a paucity of literature supporting the theory of the evolution of deep infiltrating endometriosis (Gordts et al., 2017). There are however various reports of evolving endometriotic lesions causing organ failure (bowel occlusion or ureteric obstruction) due to the progressive growth of nodules (Roman et al., 2015). Deep infiltrating endometriosis is diagnosed only rarely in adolescent patients, while the mean age of patients undergoing management of rectal endometriosis averages 33 years. This suggests that the development of deeply infiltrating lesions may occur between 20 and 30 years of age (Roman et al., 2015; Torralba-Morón et al., 2016; Abo et al., 2018; Vallée et al., 2018). Therefore, no definitive conclusions can be drawn as to whether deep infiltrating endometriosis is a progressive disease or not. Despite this apparent lack of evidence, there is consensus about a presumed slow progression of deeply infiltrating endometriosis (Leyland et al., 2010; Dunselman et al., 2014; Collinet et al., 2018).

The medical treatment of the symptoms of endometriosis is based on the inhibition of ovulation, the interruption of menstruation and the stabilization of the steroid hormone milieu (Vercellini et al., 2014). Various treatments can be used to achieve amenorrhoea and their efficacy in reduction of pain has been well established (Fedele et al., 1993; Vercellini et al., 1993; Leone Roberti Maggiore et al., 2014). However, the influence of amenorrhoea on disease progression remains unknown (Vercellini et al., 2011). This influence can only be argued on the basis of pathophysiology: it has been postulated that the interruption of retrograde menstruation and the inhibition of inflammation and the secretion of biosteroid hormones may prevent the progression of the disease and the occurrence of new lesions.

We conducted a retrospective study on patients with rectosigmoid endometriosis who had not undergone surgical management and had successive pelvic MRI examinations to follow the natural evolution of deep infiltrative lesions. The aim of this study was to assess the risk of progression of deep endometriotic nodules infiltrating the rectosigmoid and to evaluate the influence of continuous amenorrhoea on their development.