Epidemiology
A rare tumor of adults, usually superficial or in the subcutaneous tissue, with a preference for the lower limbs. The mix of old blood and dilated vessels can make it look like a persistent hematoma rather than a tumor.
Basic features
It is usually a slow-growing mass with dilated blood vessels, bleeding-related changes, and marked cellular atypia under the microscope.
Usual treatment
Management is complete removal with adequate margins, along with pathology correlation to rule out a higher-grade sarcoma.
Outcomes and prognosis
It can recur locally fairly often; so far, spread to distant sites (metastasis) has not been described.