LAUSR

projections, comparable to the proliferative activity of intradermal nodular fasciitis. Mehregan reported that nodular fasciitis is histopathologically composed of a central solid mass with many irregular projections extending outward into the surrounding fatty tissue, thus indicating a highly invasive growth. Therefore the US findings of an irregular margin with string-like projections seem to correspond well to these histological features. The localized clear blood-flow signals detected by colour Doppler US represent the pronounced dilatation of blood vessels and hypervascularity seen by histological examination. In addition to skin cancers and inflammatory/infectious diseases, benign skin tumours (haemangioma, etc.) are known to show increased blood flow signals on colour Doppler US. Intradermal nodular fasciitis therefore should be considered as one of the skin tumours with malignant features that can be seen with colour Doppler US.