Lung cancer, proptosis, and decreased vision

A 48-year-old man presented to the emergency department with a 3-day history of decreased vision in a painful proptotic right eye. The patient was being treated with chemotherapy and radiation for non-small cell lung carcinoma. Examination showed visual acuity of hand motions, decreased motility, and an afferent pupillary defect on the right, consistent with an orbital apex syndrome. Neuroimaging revealed "dirty" orbital fat and no paranasal sinus disease. Orbital biopsy initially showed only fibrosis; however, on subsequent biopsies, nonseptate hyphae later identified as mucormycosis was recovered. The patient survived with exenteration and systemic amphotericin B.