Objective:To evaluate the clinical significance of morular metaplasia (MM) in fertility-preserving treatment for young patients with endometrial hyperplasia and grade 1 endometrial endometrioid carcinoma.Methods:Clinical data was retrospectively collected from patients diagnosed with endometrial hyperplasia or grade 1 endometrial endometrioid carcinoma under 40 years old who underwent progestin-based fertility-sparing treatmentat in Tianjin Medical University General Hospital between January 2018 and November 2022.Patients were divided into the MM group (37 cases) and the non-MM group (63 cases) based on pathological findings. Clinical characteristics, hysteroscopic features, treatment efficacy and fertility outcomes were compared between the two groups. The MM group was further stratified into three subgroups based on the timing of MM occurrence:(1) MM-Bef group ( n=10): MM was present in the initial endometrial curettage or hysteroscopic biopsy pathology before fertility-sparing treatment and disappeared after treatment; (2) MM-Sus group ( n=14): MM persisted consistently before and after therapy;(3) MM-Aft group ( n=13): MM was absent before therapy but appeared after treatment. The risk factors which had impact on the treatment outcomes of the patients were analyzed using univariate and multivariate Cox regression analysis. Results:The rate of polycystic ovary syndrome were higher in the MM group than the non-MM group [51% (19/37) vs 27% (17/63), P=0.014]. The complete response (CR) rate was significantly lower in the MM group than in the non-MM group [73% (27/37) vs 95% (60/63), P=0.006], and the median time to CR was significantly longer in the MM group (6.0 vs 5.0 months, P=0.005).Multivariate analysis identified that MM-Sus ( HR=0.355, 95% CI:0.174-0.723; P=0.004) and MM-Aft ( HR=0.314, 95% CI:0.145-0.681; P=0.003) were independent risk factors for delayed CR in fertility-sparing treatment. The patients in the MM group and non-MM group underwent hysteroscopic biopsy for 76 and 131 times. "Gravel-like change" was a more frequent hysteroscopic manifestation in the MM group than that in the non-MM group [18% (14/76) vs 2% (2/131), P<0.001]. Conclusions:Patients in the MM group have poorer treatment outcomes than patients in the non-MM group. MM-Sus and MM-Aft are risk factors for fertility-preserving treatment in young patients with endometrial hyperplasia or grade 1 endometrial endometrioid carcinoma. "Gravel-like change" is the characteristic hysteroscopic manifestations of MM.

Objective:To evaluate the clinical significance of morular metaplasia (MM) in fertility-preserving treatment for young patients with endometrial hyperplasia and grade 1 endometrial endometrioid carcinoma.Methods:Clinical data was retrospectively collected from patients diagnosed with endometrial hyperplasia or grade 1 endometrial endometrioid carcinoma under 40 years old who underwent progestin-based fertility-sparing treatmentat in Tianjin Medical University General Hospital between January 2018 and November 2022.Patients were divided into the MM group (37 cases) and the non-MM group (63 cases) based on pathological findings. Clinical characteristics, hysteroscopic features, treatment efficacy and fertility outcomes were compared between the two groups. The MM group was further stratified into three subgroups based on the timing of MM occurrence:(1) MM-Bef group ( n=10): MM was present in the initial endometrial curettage or hysteroscopic biopsy pathology before fertility-sparing treatment and disappeared after treatment; (2) MM-Sus group ( n=14): MM persisted consistently before and after therapy;(3) MM-Aft group ( n=13): MM was absent before therapy but appeared after treatment. The risk factors which had impact on the treatment outcomes of the patients were analyzed using univariate and multivariate Cox regression analysis. Results:The rate of polycystic ovary syndrome were higher in the MM group than the non-MM group [51% (19/37) vs 27% (17/63), P=0.014]. The complete response (CR) rate was significantly lower in the MM group than in the non-MM group [73% (27/37) vs 95% (60/63), P=0.006], and the median time to CR was significantly longer in the MM group (6.0 vs 5.0 months, P=0.005).Multivariate analysis identified that MM-Sus ( HR=0.355, 95% CI:0.174-0.723; P=0.004) and MM-Aft ( HR=0.314, 95% CI:0.145-0.681; P=0.003) were independent risk factors for delayed CR in fertility-sparing treatment. The patients in the MM group and non-MM group underwent hysteroscopic biopsy for 76 and 131 times. "Gravel-like change" was a more frequent hysteroscopic manifestation in the MM group than that in the non-MM group [18% (14/76) vs 2% (2/131), P<0.001]. Conclusions:Patients in the MM group have poorer treatment outcomes than patients in the non-MM group. MM-Sus and MM-Aft are risk factors for fertility-preserving treatment in young patients with endometrial hyperplasia or grade 1 endometrial endometrioid carcinoma. "Gravel-like change" is the characteristic hysteroscopic manifestations of MM.