Solitary infantile myofibromatosis involving the clavicle

A rare case of solitary infantile myofibromatosis of bone is reported in th e right clavicle of a 15-year-old boy. A radiograph demonstrated an osteoly tic lesion with a sharp margin and a sclerotic rim. CT revealed a circumscr ibed lesion with slight expansion of the cortex. On MRI the lesion appeared isointense to muscle on T1-weighted images, bright on T2-weighted images, and showed marked gadolinium enhancement. The patient was well, without evi dence of recurrence or metastasis, 4 years and 5 months following resection .