MET exon 14 skipping gene-positive lung adenocarcinoma associated with atypical adenomatous hyperplasia in lungs and metachronous lung adenocarcinoma.

BACKGROUND

Recently, there has been interest in the CT imaging characteristics of lung cancer positive for mesenchymal-epithelial transition (MET) exon14 skipping mutation. Herein, we present a patient with MET exon 14 skipping gene-positive lung adenocarcinoma associated with multiple ground-glass opacities (GGOs) in both lungs and metachronous contralateral lung adenocarcinoma.

CASE: A 67-year-old man was referred to our hospital due to abnormal finding on chest radiograph. A chest CT on admission revealed a mass in the right lung. A chest CT scan showed a mass in the middle lobe of the right lung, and numerous GGO nodules of various sizes in both lungs. The mass was resected and it was diagnosed as a MET exon 14 skipping gene-positive invasive adenocarcinoma. A GGO nodule resected at the same time was pathologically diagnosed as atypical adenomatous hyperplasia (AAH). A GGO nodule in the left lung that was present at the initial consultation grew in size on a CT scan performed 1 year and 4 months after the right lung resection, and was therefore resected. The nodule was pathologically diagnosed as a MET exon 14 skipping gene-negative invasive adenocarcinoma. Genetic testing for an AAH adjacent to the second adenocarcinoma was negative for the MET exon 14 skipping gene.

CONCLUSION

The clinical course of this patient was interesting clinical information in terms of providing insight into the morphology, imaging findings, and origin of MET exon 14 skipping gene-positive adenocarcinoma.