Extensive hematoma of the vastus intermedius showing components of subacute and chronic hemorrhage with associated myositis of the vastus intermedius and medialis.

The MRI appearance of hematomas is variable and depends on the age of the hematoma. Subacute to chronic hematomas demonstrate increased signal on T1-weighted images, placing them on a short list of entities that may demonstrate this imaging characteristic, namely fatty lesions, hemangioma, hematoma and intralesional hemorrhage. Distinguishing a simple soft tissue hematoma from a hemorrhagic neoplasm is critical for proper patient management, but is often difficult. Our patient's presenting history and imaging findings were characteristic of hematoma, and our patient was managed nonoperatively, and discharged after being observed in the hospital for 48 hours. When imaging is inconclusive, or clinical history equivocal, it is important to exclude an underlying hemorrhagic soft tissue sarcoma, by follow-up to resolution.