Differentiated thyroid carcinoma (DTC) is the most common endocrine tumor, characterized by high incidence, low recurrence rate, and low mortality. Locally advanced thyroid cancer (LATC) is rare in clinical practice, with poor prognosis, and is one of the leading causes of death among thyroid cancer patients. In August 2024, the Thyroid Surgery Department of China-Japan Union Hospital of Jilin University admitted a 61-year-old male patient with a history of "neck mass surgery 16 years ago and progressive enlargement with ulceration of the mass over the past 3 months." Physical examination revealed an irregularly shaped mass measuring approximately 12 cm × 12 cm in the left supraclavicular fossa, with a dark red surface, ulceration, bleeding, and necrotic exudate in some areas. After admission, a multidisciplinary team (MDT) consultation was initiated, and the patient underwent his fifth surgery, which included resection of the left cervical mass, left cervical lymphadenectomy, resection of a submental mass, and free flap transplantation. The patient was discharged on postoperative day 10 in good condition. One month after surgery, a follow-up ultrasound at our hospital showed no significant abnormalities in the neck, with good healing of the local skin and survival of the transplanted flap. This article reviews the MDT treatment process of this LATC case and summarizes the characteristics of LATC based on domestic and international literature, providing experience and references for the comprehensive treatment of this disease.