[Distant metastases to maxillary sinus from an unknown lung adenocarcinoma: a cases report]

A 59-year-old man was admitted to the Department of Ear, Nose and Throat with a complaint of six-month history of left facial numbness and toothache. There was no special previous medical history in addition to smoking. No obvious abnormality in routine electrocardiogram, chest X-ray, abdominal B ultrasound were found. (1) CT scans showed heterogeneous shadows in maxillary sinus with the lesions on the left max- illary bone and evidently destruction of alveolar bone. The histopathological examination revealed bone tissue which was partly covered by an intact adenocarcinoma cell. (2) Immunohistochemical staining foe CK7, CD117, thyroid transcription factor-1, and novel aspartic proteinase A were positive and thus compatible with metastatic lung adenocarcinoma. (3) Chest CT scans showed a 1 cm x 2 cm mass on the superior lobe of the left lung, with destruction of sternum and rib, confirming that the lesions in the paranasal sinuses were lung cancer metastases. Therefore, this patient conclusively diagnosed as lung adenocarcinoma with multiple bone metastases.