High-resolution and color Doppler sonography in the evaluation of skin metastases

Objective. To evaluate high-resolution sonography in differentiating cutaneous metastases from other benign dermatologic diseases with the final objective of proposing high-resolution sonography in the diagnostic protocol for asymptomatic patients and those with neoplasms who have 1 or more rapidly growing skin nodules. Methods. We selected 57 patients (24 women and 33 men, mean age +/- SD, 53 +/- 25 years) who underwent high-resolution and color Doppler sonography because they recently noticed 1 or more superficial nodules. Patients were mostly asymptomatic, but 15 had previously diagnosed malignancies. Each nodule was classified by measurement of fundamental sonographic parameters (major diameter, shape, borders, echo texture, and homogeneity) and by assessment of vascularity (presence or absence of flow and vascular pattern) with color Doppler sonography. All nodules were ablated and histologically examined. Results. Of 68 nodules, 23 were malignant (21 metastases and 2 B-cell lymphomas), and 45 were benign (22 sebaceous cysts, 18 granulomas of different origins, 3 fibromas, and 2 neurofibromas). The nodules were all localized in the subcutaneous space, had clearly demarcated borders, and were hypoechoic; a circular or oval shape was predominant, but 7 metastases had an irregular, polycyclic shape. On color Doppler sonography, none of the benign nodules or B-cell lymphomas showed signs of vascularity, whereas the metastatic nodules were all vascularized, with 1 or more peripheral poles (21 of 21 nodules) and internal vessels (11 of 21 nodules). Conclusions. A polycyclic shape and hypervascularity, with multiple peripheral poles and, eventually, internal vessels, should be considered the most indicative signs of metastasis.