Ovary metastasis from lung cancer mimicking primary ovarian cancer: A rare case report

•Ovarian metastasis from lung cancer is very rare, which might lead to a misdiagnosis as primary ovarian cancer.•In this circumstance, thorough systemic assessment and immunohistochemistry are essential to confirm the primary.•Our clinical case provides a lesson learned in diagnosing and treating lung cancer, which has a unique and rare clinical presentation.