Adult Onset Xanthogranuloma With Frontal Nerve and Intracranial Involvement.

Adult-onset xanthogranuloma (AOX) typically affects the preseptal and anterior orbital regions. The authors report a 49-year-old man with a 6-month history of unilateral AOX, demonstrating diffuse extraconal and intraconal orbital involvement, including the lacrimal gland and extraocular muscles. There was frontal nerve enlargement, intracranial and pterygopalatine fossa involvement. Investigations excluded IgG4 disease and Erdheim-Chester disease. This case illustrates that AOX may be added to the causes of orbital nerve enlargement and may demonstrate intracranial extension.