Thorough pathological examination is the best practice to examine chronic hematomas suspicious for masquerading cystic soft-tissue sarcomas

Cystic soft-tissue sarcomas have been known to mimic chronic hematomas in clinical and radiological presentation. We report two cases of space-occupying masses previously diagnosed as chronic hematomas, but presenting with recent changes raising concern for malignancy. Preoperative imaging was inconclusive in both cases, leaving biopsy the only possible method of diagnosis. Excisional biopsy of one case confirmed the diagnosis of chronic hematoma. However, in the other case an incisional biopsy was performed and over 90% of the biopsy sample was hemorrhagic and necrotic, resulting in an indeterminate diagnosis. The final diagnosis of high-grade angiosarcoma could only be made after the mass was completely excised and meticulously examined. A thorough specimen sampling technique was used instead of the traditional excisional biopsy sampling techniques. We propose that the best practice to prevent misdiagnosis of a possible soft tissue sarcoma masquerading as a chronic hematoma is to completely excise and thoroughly examine the mass.