Patients with angiosarcomas of the head and neck often present with nonspecific symptoms, such as enlarging bruises, blue-black nodules, or unhealed ulceration. We present the case of a 79-year-old man with diffuse head, neck, and left parotid gland swelling who was initially diagnosed as having superior vena cava syndrome. Computed tomography revealed subcutaneous soft tissue thickening at the scalp, orbital regions, and face. Immunohistochemical examination of tissues biopsied from the scalp and parotid tissues confirmed angiosarcoma. Because the tumour was unresectable, the patient opted for Intensity-Modulated Proton Therapy (IMPT) at another hospital, and a favorable response was observed. This case highlights the diverse and heterogeneous presentations of angiosarcoma in the head and neck, indicating that IMPT could serve as a viable treatment option for unresectable angiosarcoma. (J Taiwan Otolaryngol Head Neck Surg 2023; 58:167-172)
