Chronic expanding hematoma of the thigh simulating neoplasm on gadolinium-enhanced MRI.

Patients who present with slowly growing extremity masses are often imaged with MRI to be examined for possible tumors. In addition to cysts and neoplasms, chronic expanding hematomas should be considered in the differential diagnosis if the patient has a history of remote trauma. The presence or absence of internal contrast enhancement is often used to distinguish between hematomas and hemorrhagic neoplasms on MRI and CT. We present the unusual case of a patient who had a chronic expanding hematoma of the calf that demonstrated nodular internal enhancement on gadolinium-enhanced MRI, simulating a neoplasm.