Integrative analysis of cutaneous skin tumours using ultrasonogaphic criteria. Preliminary results.

THE AIM of this study is to identify the US features of skin tumors, especially morphological and vascular, in order to develop an integrative and differentiating imaging model for benign and malignant skin tumors. MATERIAL AND METHOD Twenty three patients with solid skin tumors were included in the study. The diagnostic procedures were clinical examination, dermoscopy, multimodal ultrasonography (US), using high frequency and conventional US, contact elastography, and i.v. contrast enhanced ultrasound (CEUS). RESULTS The US characteristics of the basal cell carcinomas were: hypoechoic, inhomogeneous masses, with hyperechoic or anechoic areas, depending on the histological differentiation, increased rigidity, uneven vascularization at Doppler examination, central or mixed type circulatory model, with 1-2 supply vessels, velocity >2 cm/s, intensely inhomogeneous load of the contrast agent (CA) and quick wash out time. The benign tumors were hypoechoic or echoic masses, with inhomogeneous structure, Doppler signal present only in dermofibromas, peripheral circulation model, velocities < 2.00 cm/s, a weak and uneven loading of the CA in the vascular bed, and a slow wash out time. Analysis of the CA dynamics evidenced a significantly higher value for the wash out time in the malignant tumors (38.2s+/- 15.15) as compared to the benign ones (54.2s +/- 8.5). Particularly the tumor thickness examination by HFUS evidences an ultrasound index that may be considered as a statistically significant predictive factor (p<0.05), highly sensitive (r =0.97) for the non-invasive assessment of the histological Breslow index. Elastography did not represent a differentiation examination in the cases studied. CONCLUSIONS Ultrasound allows a complex, multimodal approach of skin tumors, which completes clinical and histological examinations, orients the therapeutic management and may assess the therapeutic efficacy and the tumoral prognosis.