Fig. 1

Typical CT images of synchronous multiple primary lung cancers. A On preoperative CT of a 67-year-old male patient shown a 13*8 mm cystic nodule (white arrow) in the right upper lobe, and B a 5 mm solid nodule (white arrow) in the S8 segment of right lower lobe. Patient received right upper lobectomy and systemic lymph node dissection in July 2019 and confirmed as adenocarcinomas (80% acinar adenocarcinoma, 10% solid adenocarcinoma) on surgical pathology, pT1bN0M0, IA2. The small solid indetermined nodule of the S8 segment of right lower lobe was followed up. C 5 months later, the nodule had grown up to a 10 mm cystic nodule. D 14 months later, this nodule had grown up to a 24*20 mm solid nodule and with multiple N2 lymph node enlargement, CT guided core needle biopsy shown acinar predominant adenocarninoma. This patient was diagnosed with synchronous multiple primary lung cancers. Because of multiple N2 lymph node metastasis and no driver gene mutation, he received Anti-PD-1 Therapy plus Chemotherapy