Clavicular fracture with delayed union after neck dissection and postoperative chemoradiotherapy: a case report

Introduction Clavicular fracture after neck dissection is rare, and postoperative radiotherapy may impair bone union. Case presentation A 71-year-old woman with tongue squamous cell carcinoma underwent partial glossectomy and radical neck dissection for cervical lymph-node metastasis. Extranodal extension led to chemoradiotherapy with 66 Gy and weekly cisplatin. Near treatment completion, right clavicular pain and erythema developed without direct trauma. Computed tomography showed a medial clavicular fracture with soft-tissue swelling but no clear metastasis or recurrence. Conservative treatment was chosen because displacement was minimal and the patient declined immobilization. Serial imaging demonstrated persistent pain, delayed union, and progressive fragment displacement. Conclusion Clinicians should consider medial clavicular fracture after neck dissection, especially following radiotherapy, when clavicular pain, erythema, or swelling appears even without trauma. Early imaging, orthopedic consultation, immobilization, and follow-up are essential to distinguish this complication from recurrent disease and to monitor healing, displacement, symptoms, and the need for further intervention.