MRI analysis of androgen insensitivity syndrome

Androgen insensitivity syndrome (AIS) is a rare disorder of sex development, and accurate preoperative imaging assessment is crucial for clinical decision-making. This study aimed to describe the magnetic resonance imaging (MRI) features of AIS, correlate imaging findings with surgical and pathological results, and evaluate the preoperative value of MRI in AIS.

This retrospective study analyzed the clinical data and preoperative MRI images of 12 patients with androgen insensitivity syndrome diagnosed through chromosomal karyotyping and confirmed by surgical exploration at our hospital between December 2018 and April 2026; gonadal pathological results were available for most gonads.

All patients were definitively diagnosed with AIS based on chromosomal karyotyping, laboratory examinations, as well as surgical exploration, with pathological confirmation obtained for most gonads, including 11 cases of complete androgen insensitivity syndrome (CAIS) and 1 case of partial androgen insensitivity syndrome (PAIS). MRI revealed a blind-ending vagina and dysplastic gonads located in the pelvis or inguinal region in all patients. The gonads showed isointense signal on T1-weighted images (T1WI), slightly hyperintense signal on T2-weighted images (T2WI), hyperintensity on diffusion-weighted images (DWI), and hypointensity on apparent diffusion coefficient (ADC) maps. Mild to moderate enhancement was observed on contrast-enhanced images. MRI achieved accurate localization of all dysplastic gonads confirmed by surgical exploration in this cohort (21/21). MRI demonstrated the absence of the uterus and ovarian structures in the pelvic cavity of patients with CAIS. However, MRI in the patient with PAIS revealed a short penis and a strip-like abnormal signal behind the bladder, which was confirmed intraoperatively as tissue resembling the uterus. Only one patient showed severe right perigonadal hydrocele on MRI, with an underlying compressed nodule that exhibited isointense signal on T1WI, slightly hyperintensity on T2WI, hypointensity on DWI, hyperintensity on ADC maps, and rapid marked enhancement. Histopathological examination ultimately confirmed a Sertoli-Leydig cell tumor (SLCT).

MRI is a reliable preoperative imaging modality for the localization of dysplastic gonads in AIS, with non-contrast sequences generally being sufficient. Contrast-enhanced imaging may offer complementary information for identifying potential Müllerian remnants or concurrent lesions in selected cases.