Metastatic Squamous Cell Lung Carcinoma to the Optic Nerve Sheath Mimicking Retrobulbar Optic Neuritis.

Lung carcinoma is the second most common malignancy in both men and women, and may metastasize to the orbit relatively early in the disease course. Metastasis to the optic nerve or its sheath is an exceedingly rare occurrence, and diagnosis may be complicated by nonspecific clinical and radiographic features. The authors present a case of squamous cell lung cancer metastatic to the optic nerve sheath, initially diagnosed as optic neuritis based on its equivocal clinical and radiographic features. This is the first histopathologically confirmed case of squamous cell lung cancer metastatic to the optic nerve sheath in the literature.