A prospective study on contrast-enhanced magnetic resonance imaging of testicular lesions: distinctive features of Leydig cell tumours.
Manganaro L., Vinci V., Pozza C., Saldari M., Gianfrilli D., Pofi R., Bernardo S., Cantisani V., Lenzi A., Scialpi M., Catalano C., Isidori AM.
ObjectivesUp to 20 % of incidentally found testicular lesions are benign Leydig cell tumours (LCTs). This study evaluates the role of contrast-enhanced magnetic resonance imaging (MRI) in the identification of LCTs in a large prospective cohort study.Materials and methodsWe enrolled 44 consecutive patients with at least one solid non-palpable testicular lesion who underwent scrotal MRI. Margins of the lesions, signal intensity and pattern of wash-in and wash-out were analysed by two radiologists. The frequency distribution of malignant and benign MRI features in the different groups was compared by using the chi-squared or Fisher's exact test. Sensitivity, specificity, positive and negative predictive value, and diagnostic accuracy were calculated.ResultsThe sensitivity of scrotal MRI to diagnose LCTs was 89.47 % with 95.65 % specificity; sensitivity for malignant lesions was 95.65 % with 80.95 % specificity. A markedly hypointense signal on T2-WI, rapid and marked wash-in followed by a prolonged washout were distinctive features significantly associated with LCTs. Malignant lesions were significantly associated with blurred margins, weak hypointense signal on T2-WI ,and weak and progressive wash-in. The overall diagnostic accuracy was 93 %.ConclusionsLCTs have distinctive contrast-enhanced MRI features that allow the differential diagnosis of incidental testicular lesions.Key points• MRI is able to characterize testicular lesions suggesting a specific diagnosis. • Rapid and marked wash-in is a common feature of Leydig cell tumours. • Markedly hypointense T2-WI signal is significantly correlated with benign lesions. • Blurred margins and weak hypointense T2-WI signal are correlated with malignant tumours. • Weak and progressive wash-in features are present in 85 % of seminomatous lesions.