Endocrine Abstracts

Background/aims: Individuals with 45.X/46,XY and several forms of 46,XY differences of sex development (DSD) have an increased risk of gonadal germ cell cancer (GGCC). Previously prophylactic gonadectomy was commonly performed but this is now more often delayed or declined. Thus, more individuals require lifelong gonadal management. Although monitoring protocols have been published, mostly based on self-examination or (bi)annual imaging with or without serum tumor marker screening, their implementation in clinical practice remains unclear. This care evaluation aims to assess adherence to recommendations for gonadal monitoring and its yield.

Methods: All individuals with 45,X/46,XY or 46,XY DSD with retained gonads were included. Data from 2020-2025 on imaging (ultrasound and/or MRI), tumour markers beta hCG and alpha-fetoprotein, and gonadal surgery were collected.

Results: Fifty-eight individuals had gonads in situ. Their median age in 2025 was 15.5 years (IQR 10–18); forty were registered as male (69%), the others as female; gonads were abdominal/inguinal in 21 (36%) and labioscrotal in 37 (64%). Twenty-two (38%) had 45,X/46,XY or XY gonadal dysgenesis, considered high-risk diagnoses for GGCC, the others had forms of XY DSD considered at lower risk. During the five-year period, 33 (57%) underwent ≥1 ultrasound and three (5%) an MRI. No findings suspicious for malignancy were reported. Imaging was more frequent for inguinal/abdominal vs labioscrotal gonads but similar between high-risk vs low-risk diagnoses and age groups <15 vs ≥15 years. Nine individuals (16%) underwent serum tumour marker screening with normal or marginally elevated results. Five patients (8.6%) eventually underwent prophylactic gonadectomy; none had a pre-malignancy or malignancy.

Conclusions: A substantial proportion of patients did not receive gonadal imaging, with no differences between high-risk vs low-risk diagnoses or age groups. For labioscrotal gonads imaging was less common, possibly because self-examination was advised as an alternative but this was not assessed. No evidence of malignancy was detected on imaging or based on serum tumour markers, which were only determined in a minority. The variability in follow-up of individuals with DSD with retained gonads may be due to the absence of evidence-based guidelines. Uniform implementation of follow-up recommendations and periodic evaluation of screening outcomes will help improve care.