[A case of primary lung cancer with initial symptoms due to orbital metastases].

We encountered a case of lung cancer in which symptoms due to orbital metastasis were recognized. A 55-year-old man presented with a chief complaint of double vision. Orbital MR image demonstrated a right intraorbital mass with bone destruction, which resulted in oculomotor nerve palsy and optic nerve disturbance. Chest CT scan showed a 4 cm mass in the right S6, which was diagnosed on biopsy as a poorly differentiated adenocarcinoma. A whole-body scintigram revealed multiple bone metastases: the right orbital wall, the lower cervical spine, the left knee joint, and so on. Based on the clinical findings, we believed that the orbital tumor was a metastasis from the lung. Systemic chemotherapy and irradiation of the right orbital tumor and the left knee joint were performed. Though a favorable response was achieved in ocular movement, the patient died 3 months after initial treatment because of progression of the primary lesion. Including this case, seventeen reported cases in which lung cancer metastasized to the orbit in Japan were also reviewed.