Qualitative and quantitative contrast-enhanced ultrasonography for the characterisation of non-palpable testicular tumours

Abstract

To assess the diagnostic performance of conventional ultrasound (US) and contrast-enhanced ultrasonography (CEUS) in the differential diagnosis of non-palpable intratesticular tumours. The local ethics review board approved the protocol, and all of the patients provided written informed consent. Between December 2011 and February 2014, men with non-palpable testicular tumours and normal tumour markers who were referred for surgery were included. The tumours were analysed by conventional US, including B-mode and colour Doppler US (CDUS) as well as by CEUS. Morphological aspects and qualitative and quantitative CEUS criteria, based on visual enhancement and time-intensity curves, were assessed for each lesion. Forty patients were ultimately included. Based on histopathological results, the tumours were classified into three groups: benign tumours (n=16), malignant tumours (n=15), and burned-out tumours (n=9). In B-mode, the morphological aspects were significantly different between benign and malignant tumours (p-values from 0.0002 to 0.008). Qualitative and quantitative analyses of the CEUS images revealed that burned-out tumours exhibited significantly less enhancement than malignant and benign tumours: in burned-out tumours, time-intensity curves were flat, whereas in both benign and malignant tumours the curves had a bell-shaped pattern. All intensity parameters were lower for burned-out tumours compared to benign and malignant tumours (p-value from 0.0001 to 0.026). Both benign and malignant tumours enhanced strongly, however, and no significant difference between the two was noted (p-value from 0.0721 to 0.0953). Unlike conventional US, which enable benign lesions to be differentiated from malignant or burned-out tumours, CEUS failed to enabled differentiation between benign lesions and malignant vascularised testicular tumours. CEUS appears to have the potential, however, to differentiate burned-out tumours from vascularised testicular tumours.