Ultrasound Appearances of Dermatofibrosarcoma Protuberans

To analyze the ultrasound appearances of dermatofibrosarcoma protuberans (DFSP) and correlate these with pathologic findings. Nine tumors in eight patients were analyzed (one patient having two separate DFSP tumors). All ultrasound images were assessed and correlated with the histologic findings. Most (7/9, or 78%) tumors were located in the subcutaneous region. The shape of the tumor was round in 67% (6/9) and ovoid in 33% (3/9) of cases. The margin was poorly defined in one (11%) and well-defined or circumscribed in eight (89%) tumors. All the tumors showed a mildly lobulated border and had a heterogeneously hypoechoic matrix, often with rounded, ovoid, or occasionally linear discrete hypoechoic areas. Very small echogenic foci (<0.5 mm), usually without an accompanying comet tail artifact, were seen within the tumor matrix of all the cases. Posterior enhancement was also a feature of all the tumors. Most (67%) tumors showed moderate vascularity on color Doppler imaging. This vascularity tended to be more profound peripherally rather than centrally, and tended to be more organized rather than chaotic in distribution. Based on its quite characteristic ultrasound appearances, one should be able to either diagnose, or at least suggest, the likelihood of a DFSP tumor. In such circumstances, either percutaneous biopsy or en-bloc resection with wide margins is recommended.