Complete response of a giant metastatic neck mass in tonsillar squamous cell carcinoma achieved with radiotherapy combined with immunotherapy: a case report.

Tonsillar squamous cell carcinoma (SCCT) is generally sensitive to chemoradiotherapy; however, treating advanced, resistant lesions remains challenging. This report presents a case of a 57-year-old male with SCCT. At initial diagnosis in May 2022, only small metastatic lymph nodes were observed in right neck levels II and III. The patient declined surgery and radiotherapy. From June to August 2022, he received 4 cycles of albumin-bound paclitaxel + cisplatin chemotherapy combined with tislelizumab, followed by tislelizumab plus capecitabine treatment from September 2022 to May 2023. Treatment was voluntarily interrupted from June 2023 to March 2024 due to intolerance, totaling approximately 18 months. By November 2024, the right neck mass had progressed into a giant, fused lesion measuring 12.27 × 7.85 cm. Subsequently, radiotherapy to the tonsillar primary bed (GTV 60 Gy in 20 fractions) combined with camrelizumab was administered. After 20 fractions, clinical examination and imaging confirmed near-total resolution of the mass, with good skin healing, achieving a complete response and leaving only mild skin fibrosis. As of April 15, 2025, there was no evidence of local recurrence or distant metastasis. This case suggests that in a heavily pretreated patient with traditionally treatment-resistant, rapidly progressing SCCT and an ultra-bulky metastatic mass, the combination of radiotherapy and immunotherapy was associated with a complete response. However, given the multiple prior lines of systemic therapy, the contribution of immune priming or delayed immunotherapeutic effects cannot be excluded. Nevertheless, this observation highlights a potential synergistic opportunity for similar advanced patients.