Liposarcomas are rare mesenchymal tumors that usually develop in lower extremities or retroperitoneum; cervico-mediastinal presentation is quite uncommon. These neoplasms are commonly diagnosed at a late stage because they remain asymptomatic until nearby structures are compressed. This makes radical excision particularly challenging. To date, alternative chemoradiotherapy protocols have not yet been standardized. We report a case of a 55-year-old man with a right laterocervical mass and without substantial symptoms. Fine-needle aspiration cytology results were compatible with a well-differentiated liposarcoma. Contrast-enhanced magnetic resonance imaging revealed the magnitude of the mass, which was expanding into the mediastinum; displacing the trachea, esophagus, cervical neurovascular bundle, and thoracic aorta; and encasing the brachiocephalic artery. Compression of the left brachiocephalic vein resulted in a focal enhancement spot in the fourth liver segment, the expression of superior vena cava compression, which can promote the development of collateral venous pathways, such as the caval-mammary-phrenic-hepatic capsule-portal venous pathway. The mass was successfully excised by a team of surgical subspecialists (otorhinolaryngologists and thoracic, cardiac, and vascular surgeons). Adjuvant tomotherapy was administered to increase local disease control. The patient remained disease-free 38 months postoperatively. This case underlines the importance of accurate preoperative radiologic evaluation in patients presenting with neck masses but without substantial symptoms. Because of the involvement of many critical structures, the cooperation of many surgical subspecialties is mandatory to achieve a satisfying oncologic outcome.