With the improvement of public health awareness and the popularization of thin-section CT, the detective rate of SMPLC with mGGNs is increasing[6][7]. Distinguishing SMPLC from intrapulmonary metastases is very difficult without surgical procedure, but it is critical because the therapeutic approach for these two conditions is entirely different[8][9]. In our case, the preoperative chest CT showed mGGNs in both lungs, with the dominant lesion in the LUL. The SMPLC was firstly considered, and the indication for surgery was clear. Postoperative pathology confirmed lung adenocarcinoma for the dominant lesion. The patient refused to undergo partial resection of the right lung for clarification. The most likely diagnosis was SMPLC, but it cannot completely rule out intrapulmonary metastasis.
Currently there is no uniform standard of surgical indication and procedure for SMPLC with mGGNs[11]. One or two-stage surgical resection has been the most effective treatment[12][13]. SBRT can be considered to achieve local control [14] [15]. Few cases of chemotherapy or target therapy have been reported, Ye etal.[16] reported a successful case of treatment for multiple pulmonary nodules. They performed surgical resection for the gefitinib insensitive lesion, and continued target therapy for sensitive lesions. Cheng etal.[17] reported a successful experience of target therapy on residual mGGNs after resection for lung adenocarcinoma. In our case, aggressive treatment was not feasible because of 28 lesions in all lobes of the right lung. There was no method to distinguish a primary lung cancer from intrapulmonary metastasis. Oral Osimertinib was adopted as target therapy. To our surprise, lesions in the right lung displayed different responses to Osimertinib. To the best of our knowledge, this is the first report of an integrated approach using surgical treatment combined with target therapy for mGGNs. It indicated that intropulmonary spread might be coexisted with multicentric origin for mGGNs. In conclusion, we report a successful strategy on the postoperative treatment for mGGNs.