Extremity soft tissue sarcomas presented as hematomas

Soft tissue sarcoma (STS) with extensive intra-tumoral hemorrhage is an infrequently described entity, usually misdiagnosed as intra-muscular hematoma. The outcomes in this group of patients have not been previously described.

We retrospectively identified 15 patients, with initial clinical or imaging diagnosis of hematoma, or hematoma versus hemorrhagic sarcoma, although final diagnosis of high-grade STS was established in all cases.

The most common location was the thigh. Three patients had a bleeding predisposition. Ten patients were referred for further evaluation with the initial diagnosis of muscle strain/hematoma, hematoma versus abscess in one, whereas four were referred for soft tissue mass evaluation. Final diagnosis was made by one biopsy in only 53% of patients. Mean time to diagnosis for patients with two biopsies was 7 months from initial presentation. Histologic diagnosis was malignant fibrous histiocytoma in ten patients. Surgical treatment included tumor resection in eleven and amputation in three patients. One patient had lung metastatic disease at presentation and eight developed lung metastases within a median time of 7 months.

We suggest that an STS masquerading as hematoma should be suspected when the mechanism and the energy of the trauma do not justify the clinically detected severity of the injury, or the lesion does not follow the expected clinical course of resolution after initial conservative management. Bleeding predisposition does not exclude malignancy. The evacuation of hematomas should include pathologic examination of tissue. Prognosis is dismal due to early metastatic disease.