Clinical-radiological discordance after neoadjuvant chemoimmunotherapy in resectable lung squamous cell carcinoma

Introduction: Neoadjuvant chemoimmunotherapy improves pathological response in resectable non-small cell lung cancer, although post-treatment radiological assessment may be challenging. Case presentation: A 63-year-old man with a history of undifferentiated nasopharyngeal carcinoma treated with curative intent was subsequently diagnosed with stage IIB (cT3N1M0) squamous cell lung carcinoma, with a PD-L1 Tumor Proportion Score (TPS) of 95%. He received three cycles of neoadjuvant carboplatin, paclitaxel, and nivolumab. Restaging PET-CT showed a partial response of the lung lesion and the appearance of new hypermetabolic mediastinal lymph nodes suggestive of disease progression. Invasive restaging with EBUS ruled out malignancy and allowed surgery to proceed. Final pathological examination confirmed a major pathological response. Discussion and Conclusion: This case illustrates immunotherapy-related pseudoprogression and highlights the importance of integrating clinical, radiological, and pathological findings.