Tumors of the mediastinum is a collective term that includes neoplasms of various degrees of malignancy, different morphogenesis, originating from heterogeneous tissues and combined into one nosological form according to anatomical localization. Angiosarcoma is a rare malignant tumor originating from a vessel wall. In the general structure of sarcomas, its frequency is estimated at 1%. The tumor is characterized by an aggressive course, local recurrence, hematogenous metastasis, poor sensitivity to chemotherapy and radiotherapy. Surgery remains the main treatment for angiosarcomas. The article presents a clinical case. A 55-year-old patient has multiple primary malignant neoplasms: cancer of the body of the uterus pT1aN0M0 IA stage. Surgical treatment from 12.15.2020 panhysterectomy; angiosarcoma of the anterior mediastinum with lesions of the manubrium, body of the sternum and the 1st rib on the left, invasion into the left brachiocephalic vein with the formation of a tumor thrombus in it, growing into the upper lobe of the left lung, T3N0M0, G1. Surgical treatment from 08.12.2021 resection of the manubrium and body of the sternum with resection of the anterior segments I, II, III ribs on both sides, resection of the left brachiocephalic vein, removal of an anterior mediastinal tumor, atypical resection of the upper lobe of the left lung en bloc, reconstruction of the sternum and ribs with an individual titanium 3D prosthesis. The patient was discharged from the hospital in a satisfactory condition.