Adjuvant immunotherapy plus chemotherapy and maintenance immunotherapy for pulmonary lymphoepithelioma-like carcinoma with hepatitis B virus infection, KRAS mutation and high expression of programmed death ligand 1: A case report.

Pulmonary lymphoepithelioma-like carcinoma (PLELC) is a rare subtype of non-small cell lung cancer, often associated with Epstein-Barr virus (EBV) infection. It typically exhibits distinct epidemiological and molecular features compared to other lung malignancies. However, the clinical behavior and optimal therapeutic strategies for PLELC, particularly in the presence of concomitant viral infections or specific genetic mutations, remain poorly defined. This report comprehensively outlines the treatment process of a 58-year-old female patient diagnosed with PLELC in the right middle lobe of the lung. Following surgical resection, the diagnosis was confirmed as PLELC, which was found to be associated with hepatitis B virus (HBV) infection, KRAS mutation and high expression of programmed death ligand 1 (PD-L1). The patient subsequently received adjuvant treatment with immunotherapy (penpulimab) combined with chemotherapy, followed by penpulimab maintenance therapy, resulting in a progression-free survival of >44 months. At present, the patient is still alive and healthy, and can undergo regular follow-ups and re-examinations. Notably, preoperative testing showed a positive EBV status, which became negative post-surgery. This case highlights several key aspects. First, it examines the diagnostic and therapeutic characteristics of PLELC with a positive EBV test result before surgery that turned negative after surgical resection. Second, it assesses the influence of high PD-L1 expression and concurrent HBV infection on the efficacy and safety of immunotherapy. Third, it explores the clinical implications of the KRAS mutation in this unique tumor subtype. The overarching goal of this exploration is to offer valuable clinical guidance for managing this rare and understudied subtype of lung cancer, particularly in the context of multimodal therapy involving immunotherapy.