Adenomyosis in Congenital Müllerian Anomalies: Pathogenetic Insights From a Systematic Review
Stefania Saponara, Stefano Angioni, Federica Picci, Maurizio Nicola D'Alterio, Pierpaolo Nicolì, Vito Cela, Uzeyir Kalkan, Grigoris Grimbizis, Angelos DaniilidisABSTRACT
Background
Adenomyosis is a prevalent gynaecological disorder whose pathogenesis remains incompletely understood. Congenital Müllerian anomalies provide an informative in vivo model, since obstructive and non‐obstructive variants impose spatially defined alterations of intrauterine pressure, myometrial architecture, and contractility.
Objectives
To characterise adenomyosis localisation across Müllerian anomaly subtypes, assess concomitant endometriosis prevalence, and examine their topographic concordance with sites of uterine obstruction.
Search Strategy
PubMed/MEDLINE, Embase and Scopus were searched from inception to October 2025 using MeSH/Emtree and free‐text terms for adenomyosis and congenital Müllerian anomalies, without date restrictions.
Selection Criteria
Original case reports, case series, and observational studies in English explicitly describing the diagnostic modalities used for both conditions.
Data Collection and Analysis
Two reviewers independently screened and extracted data; methodological quality was assessed with the Joanna Briggs Institute tools. Data were synthesised descriptively by malformation subtype, with case‐by‐case laterality analysis where individual patient‐level data were available.
Main Results
Forty‐two studies (135 patients) were included. Unicornuate uterus predominated (102/135, 75.6%). Among patients with directly reported localisation and a non‐communicating functional rudimentary horn, adenomyosis involved the rudimentary horn in 10/12 cases (83.3%). In Robert's uterus, adenomyosis was ipsilateral to the blind hemicavity in 3/3 evaluable cases (100%). In Mayer–Rokitansky–Küster–Hauser (MRKH) syndrome, adenomyosis occurred in remnants lacking functional endometrium in 10/15 patients (66.7%). Concomitant endometriosis (43/134 evaluable patients, 32.1%) was most frequent in obstructive anomalies (Herlyn‐Werner‐Wunderlich syndrome (HWW) 3/5, 60.0%; Robert's uterus 2/4, 50.0%) and least frequent in septate uterus (0/2, 0%) and MRKH (2/15, 13.3%), localising ipsilateral to the obstruction in 9/10 (90.0%) reported obstructive cases.
Conclusions
Adenomyosis preferentially involved structurally abnormal or obstructed uterine compartments. The endometriosis gradient was compatible with impaired menstrual efflux as a shared mechanical determinant. These findings derive from a low‐quality evidence base and should therefore be regarded as hypothesis‐generating. Prospective confirmation is required, although these findings may support increased clinical awareness in women with Müllerian anomalies, particularly obstructive variants.