Long-term follow-up of tislelizumab combined with anlotinib in a single patient with metastatic type B3 thymoma: a case report.

Background: Thymoma is a rare epithelial malignancy. Type B3 thymoma confers poor prognosis largely owing to limited effective systemic therapies. Although immune checkpoint inhibitors and multi-target tyrosine kinase inhibitors have shown promising therapeutic efficacy in multiple solid tumors, yet their application in thymoma remains insufficiently investigated. Case presentation: A middle-aged woman with chest tightness and dyspnea was diagnosed with metastatic type B3 thymoma involving multiple mediastinal, hilar, and pulmonary lesions. After progression on first-line platinum-based chemotherapy, she was treated with tislelizumab and anlotinib. The combination therapy achieved a marked objective response, resulting in tumor regression, with over 30 months of progression-free survival and a maintained good quality of life. Conclusion: This case suggests that the combination of tislelizumab and anlotinib may exhibit promising antitumor activity in patients with metastatic type B3 thymoma. However, the therapeutic efficacy of this regimen cannot be established based on a single case. Therefore, further prospective studies with larger, well-controlled clinical cohorts are required to validate its safety and efficacy.