A Masquerading Hematoma Resulting in the Delayed Diagnosis of a Soft Tissue Sarcoma: A Case Report.

A 27-year-old male with insidious right arm swelling was diagnosed with a hematoma secondary to a partial biceps tear, later identified as a rhabdomyosarcoma. Soft tissue sarcomas (STS) may present with misleading patient histories and nonspecific symptoms, resulting in misdiagnosis and delayed treatment. One of the classic masqueraders of soft tissue sarcomas is hematomas secondary to trauma. Obtaining a prudent history with careful scrutiny of appropriate imaging often helps establish the correct diagnosis. Ultimately, tissue biopsy can resolve any ambiguous cases and prevent delays in diagnosis and treatment.