Mammary-type myofibroblastoma of the thigh mimicking liposarcoma.

Myofibroblastoma is a rare tumor that was originally described in the breast but has since been found in extra-mammary locations, where it been renamed mammary-type myofibroblastoma (MTM). We describe a case of MTM occurring in the anterior compartment of the thigh, which was initially interpreted as a possible a liposarcoma on MRI. Two subsequent biopsy samples and eventual excision revealed the tumor to have the characteristic pathology of MTM. This benign tumor, albeit rare, needs to be considered in the imaging differential diagnosis of fat containing deep soft tissue masses of the extremity.