Blue nevus with satellitosis mimicking malignant melanoma.

Blue nevus rarely develops a malignant melanoma. The loss of the regular border and the development of satellite lesions are ominous clinical indicators of the malignant change. A case is presented in which both of these clinical features--irregular border and satellite lesions--were present, but no malignant change was observed histopathologically. To our knowledge, such a single nodule with satellite lesions mimicking malignant melanoma has not been described previously.