Supplementary Material for: Unusual Synchronous Multiple Primary Early-Stage Lung Adenocarcinoma with Concomitant MET Exon 14 Skipping, PIK3CA and KRAS Mutations: A Case Report

<b><i>Instruction:</i></b> Synchronous multiple primary lung cancer (sMPLC) constitutes a distinct subtype of NSCLC, where accurate diagnosis and prognostic evaluation remain challenging. <b><i>Case Presentation:</i></b> The case involves a 70-year-old male patient admitted to the hospital due to bilateral pulmonary nodules. The patient underwent staged resection. Molecular pathological examination revealed that tumor A harbored concurrent mutations in MET exon 14 skipping and PIK3CA (p.E545K), while tumor B exhibited a KRAS exon 2 (p.G12S/D) mutation. Postoperatively, the patient demonstrated a favorable recovery, with no evidence of recurrence for 1 year. <b><i>Conclusion:</i></b> This study presents a case of sMPLC in early-stage lung cancer, illustrating the genetic heterogeneity in early-stage lung adenocarcinoma and underscoring the significance of precise evaluation of sMPLC and intrapulmonary metastases.