Primary angiosarcoma of superior vena cava: an unexpected diagnosis after an oncological emergency.

Angiosarcoma (AS) is a rare malignant tumour representing 1%-2% of all sarcomas. Primary AS of superior vena cava (SVC) was reported in two cases worldwide. We report a 69-year-old woman with neck discomfort, headache and dyspnoea for 3 months. CT angiography showed thrombosis in SVC and brachiocephalic veins resulting in an SVC syndrome. The patient began anticoagulant therapy and underwent balloon angioplasty with clinical improvement. Additionally, a positron emission tomography scan confirmed the presence of a mediastinal mass involving the SVC locally. The tumour was excised and a prosthesis was placed on the SVC. Histology revealed a heterogeneous tumour matrix, either myxoid and composed by fusiform cells with vimentin, homogeneous CD31 and a 30% Ki67 immunoexpression, supporting the diagnosis of an AS. Due to multiple complications, the patient never started chemotherapy, and after tumour recurrence, she died within 5 months after diagnosis.