Endocrine Abstracts

Introduction: With the improved imaging techniques, Leydig cell tumours (LCTs) are frequently found, accounting up to 22% of testicular tumours. The natural history of LCTs is relatively unknown, because of the small size and heterogeneity of available studies. Since LCTs are often removed, long-term follow-up is missing. The aim of this study was to report the experience with a large cohort of prospectively collected LCTs.

Materials and methods: Patients with LCTs were enrolled from 2005 to 2016. Clinical and biochemical features of LCTs were compared with two matched cohorts: patients with seminomas and patients without testicular lesions (noL) randomly selected among patients referred in the same period.

Results: 77 patients had LCTs, 90 had seminomas, and 1420 had no lesion (noL). Groups were matched for age and BMI. Infertility was the reason for referral in more than half of LCTs. Testicular volumes (P=0.002), sperm concentration (P=0.001) and morphology (P<0.001) were significantly lower in LCTs compared to noL; gonadotropins were higher (P<0.001) and testosterone was lower (P=0.008) in LCTs vs noL. No differences were found in gonadal steroid after hCG test, between groups. When compared to seminomas, LCTs did not show differences in hormonal status except for higher SHBG levels (P=0.028), LH/Te ratio (P<0.001), and lower sperm concentration (P=0.04). LCTs lesions were smaller compared to Sem (P<0.001). Cryptorchidism (χ²=45.658 P<0.001) and gynecomastia (χ²=54.923, P<0.001) were associated with a higher risk of LCTs. After a median follow-up of 32.5 months, no metastases have been detected. Non-operated LCTs developed subclinical hypogonadism (P=0.018) compared to surgically removed LCTs.

Conclusions: LCTs have a good prognosis when correctly recognized. Based on the largest existing series, we showed that infertility, gynecomastia,low testicular volume, and cryptorchidism are frequently associated with LCTs, supporting the hypothesis that testicular dysgenesis syndrome could play a role. Active surveillance, as an alternative to surgical removal, appears to be a safe option, but monitoring of Leydig cell failure remains necessary.