The patient was a 45-year-old woman who was diagnosed with lung adenocarcinoma and underwent surgical resection of the tumor. Four months after the tumor removal, she presented with epistaxis and left-sided headache. however, the symptoms were considered insignificant and were not investigated further. Five months after the lung surgery, the patient developed a swelling around the left eye socket, which increased progressively and was accompanied by purulent nasal discharge, nasal obstruction, decreased sense of smell, or decreased vision. Previously, the patient was found to have a right upper pulmonary mass during a routine physical examination. To rule out malignancy, thoracoscopy was performed, which revealed a mass (diameter approximately 3 cm) located in the posterior segment of the right upper lobe of the lung. Surgical removal of the tumor was successful, with resection of the right upper lobe and adjacent lymph nodes. The tumor was firm in consistency and oval, with an intact capsule. Postoperative pathological examination revealed that the lesion was a moderately differentiated lung adenocarcinoma, with no involvement of the incision margin of the bronchus and no metastasis to the lymph nodes. The patient had no previous medical history. History taking also revealed that the patient had no other relevant medical history or family history. On physical examination at presentation, the external nose was found to be normal in shape. No obstruction of the nasal passages was observed on either side, and no abnormal secretion or colonization was detected. There was no obvious tenderness over the areas of the sinuses. Results of serum tests for tumor markers were all negative. No abnormalities were noted in the coagulation indices or in the results of routine blood tests, tests for immunoglobulin light chains, thyroid hormone levels, and tests for autoimmune antibodies. Computed tomography (CT) and magnetic resonance imaging (MRI) examination of the sinus was performed, the findings revealed left maxillary sinusitis, bilateral ethmoid sinusitis, and septal deviation, with bone destruction of the left ethmoid sinus..