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


Patient Characteristics

Between September 2016 and March 2018, 86 patients with deep endometriosis infiltrating the rectosigmoid, assessed by at least two pelvic MRIs, were referred for review to one of the authors. Ten patients were excluded because the interval between the two MRIs was <12 months. Ten patients were excluded because they had undergone pelvic surgery between the two MRIs. Seventeen patients were excluded because one of their MRIs was considered to be of poor quality, which would impact on accurate repeat assessment of nodules. In six patients, a colorectal lesion could not be confirmed on one or more MRIs. A total of 43 patients were enrolled in the study. Among them, 58% had a prior history of infertility. Patient characteristics and main presenting complaints are reported in Table I and Table II, respectively.

Reproducibility of Measurements

Our results demonstrate that our method of measurement of the length and thickness of rectosigmoid nodules on MRI is reproducible. Inter-observer reliability for nodule thickness is characterized by an ICC of 0.793 (95% CI = 0.565–0.901), P < 0.001; intra-observer reliability for nodule thickness: ICC = 0.956 (0.908–0.979), P < 0.001; inter-observer reliability for nodule length: ICC = 0.904 (0.798–0.954), P < 0.001; intra-observer reliability for nodule length: ICC = 0.982 (0.962–0.991), P < 0.001.

Progression of Rectosigmoid Lesions

Mean time between MRIs was 38.3 ± 22.1 months. The mean length of rectosigmoid nodules at first MRI was 37 ± 26 mm and the mean thickness was 11 ± 5 mm. The mean height of nodules at both first and second MRI was 86 ± 21 mm. In 26 (60.5%) women, rectosigmoid nodules were stable, in 12 women (27.9%) nodules progressed, while in 5 women (11.6%) nodules regressed (Table III and Figure 2).

Figure 2.

Evolution of rectosigmoid nodules during the interval between the two MRI examinations. (a) Nodule progression, (b) nodule regression and (c) occurrence of a rectosigmoid nodule (10 cm scale marker in all panels).

Influence of Amenorrhoea

There was no significant difference in interval between MRIs between the three groups (P = 0.76). The median proportion of time where amenorrhoea occurred between MRIs was significantly different among the three groups: in women where progression of a rectosigmoid nodule between MRIs was demonstrated, amenorrhoea had occurred for a significantly lower proportion of time between MRIs (15.1%) than those with stable nodules (19.2%) and those with nodule regression (94.1%) (P = 0.006). Median number of months of amenorrhoea between MRIs tended to be lower in women with nodule progression (7.5 months, range 0–9 months) than in those with stable nodules (8.5 months, range 0–23) and nodule regression (21 months, range 13–41) (P < 0.09; Table IV).

Among the 36 women with ongoing menses during the interval, nodule growth was recorded in 12 patients (34%) and nodule regression was recorded in 3 patients (8%), while in 21 patients nodule size was stable (58%). Among 13 patients who did not experience any amenorrhoea during the interval, nodules progressed in 5 patients (39%) and were stable in 8 of them (61%). Among 7 patients with continuous amenorrhoea during the whole interval, a regression of nodule size was observed in 2 cases, while in 5 cases the size of the nodule remained stable. Thus, no patients with continuous amenorrhoea demonstrated nodule progression.

De novo rectosigmoid nodules developed between the two MRIs in a total of two patients. The first patient was a 30-year-old nullipara, with an inter-MRI interval of 93 months, during which time she reported 9 months of amenorrhoea due to pregnancy. Review of the second MRI revealed a new nodule, 21 mm in diameter, infiltrating the rectum 86 mm above the anal verge (Figure 2). The second patient was a 27-year nullipara with a history of infertility, with an inter-MRI interval of 15 months completely free of amenorrhoea. Review of her second MRI revealed a new nodule, 27 mm in diameter, infiltrating the rectum 120 mm above the anal verge.

Conversely, complete regression of a rectosigmoid nodule was recorded in a 29-year patient who had an inter-MRI interval of 34 months. During this time, she reported 32 months of amenorrhoea (15 months due to GnRH agonists and 17 months due to the continuous combined oral contraceptive pill). The first MRI revealed a nodule, 19 mm in diameter, infiltrating the rectum 104 mm above the anal verge, which was not present on the second MRI. However, this patient reported ongoing pelvic pain at the time of the second MRI.

Eight patients reported a pregnancy in the inter-MRI interval. We investigated whether or not pregnancy had a more pronounced effect on the risk of progression of endometriotic nodules than medically induced or lactational amenorrhoea (Table V); however, no significant difference was found.

No previous surgery undergone by patients enrolled in our study was for treatment of deep endometriotic nodules, but only for the purpose of diagnostic laparoscopy, treatment of superficial lesions and endometriomas or assessment of fallopian tubes. The comparison between patients who had, or had not had, prior surgery did not reveal significant differences in terms of progression or regression of deep endometriosis nodules (P = 0.098).