Ultrasound features of adenomyosis and diagnostic challenges

Adenomyosis is a common but frequently underdiagnosed gynecological disorder with significant implications for fertility and reproductive outcomes. Despite advances in imaging, accurate recognition remains challenging due to operator dependency, uterine anatomical variations, and ultrasound artifacts that may mimic disease features.

To illustrate the sonographic spectrum of adenomyosis in subfertile women using two-dimensional (2D) and three-dimensional (3D) transvaginal ultrasound, evaluate age-related differences in ultrasound lesion morphology, and identify common diagnostic pitfalls encountered during routine scanning.

A prospective observational study was conducted between 2022 and 2024 across three reproductive medicine centers. A total of 658 women aged 20-40 years undergoing infertility assessment were examined by 2D and 3D transvaginal ultrasound. After excluding 140 cases with inadequate visualization, 518 participants were analyzed. Adenomyosis was diagnosed in 149 women (28.8%) according to the Morphological Uterus Sonographic Assessment (MUSA) criteria. Ultrasound features were compared between two age groups: 20-35 years (n = 103) and 36-40 years (n = 46).

The prevalence of adenomyosis was higher in the 36-40-year group (35.9%) compared to the younger group (26.4%). The diffuse form of adenomyosis predominated (65.1%) and was significantly more frequent in the older age group (p = 0.027). Significant age-related differences were observed for myometrial cysts (87.0% vs 63.1%; p = 0.003), asymmetric wall thickening (91.3% vs 33.0%; p < 0.0001), and fan-shaped shadowing (91.3% vs 67.0%; p = 0.002). Diagnostic challenges were primarily linked to uterine rotation, retroversion, and acoustic shadowing simulating junctional zone irregularity.

Adenomyosis in subfertile women exhibits distinct age-related phenotypes, with higher prevalence in 36-40 age group. The increased frequency of specific structural markers in older women-suggests that the sonographic expression of adenomyosis progresses with age. Furthermore, the identification of diagnostic pitfalls, such as uterine retroversion and acoustic shadowing mimicking junctional zone irregularity, indicates that uterine positioning remains a critical confounding factor in the sonographic assessment of adenomyosis.