Metastatic angiosarcoma of the scalp presented as posttraumatic subgaleal hematoma: The many faces of a diagnostic challenge.

Angiosarcomas represent highly-aggressive malignant lesions of the endothelial cells of blood vessels, affecting mostly the elderly population, and usually located in the scalp or face. As cutaneous angiosarcomas often metastasize to the lung, they can manifest in various forms. We report a case of a 77-year-old male who presented after a posttraumatic blunt scalp lump that was initially diagnosed as infected subgaleal hematoma. This was later found to be an angiosarcoma. Further workup revealed that the tumor was invading the dura, with a rare pattern of mixed concomitant cystic and solid lung metastasis with ground-glass infiltrates. The patient underwent soft tissue reconstruction with split-thickness skin graft for the scalp lesion and palliative chemotherapy. We are discussing the common manifestations of scalp angiosarcomas and their potential pulmonary metastatic patterns. Also, a review of the differential diagnoses that may mimic cutaneous scalp angiosarcoma will be demonstrated.