Acute onset vision loss as a presenting manifestation of carcinoma lung

A 70-year-old lady, chronic smoker (30 pack years), with past medical history of intermittent shortness of breath along with unintentional weight loss and reduced appetite of 6-month duration, presented with episodes of severe headache of two months duration. A clinical diagnosis of metastatic adenocarcinoma of lung with SVC compression resulting in retro grade pressure on SOV causing left optic nerve compression and optic neuropathy was considered. SOV enlargement with ON compression should be suspected in lung cancer patients presenting with acute vision loss in the setting of SVC obstruction.