Superior orbital fissure syndrome caused by intraorbital spread of a cutaneous squamous cell carcinoma and not detected on computed tomography and magnetic resonance imaging

Abstract

Intraneural and perineural spread of a squamous cell carcinoma of the frontal region via the orbit to the cranial cavity is a rare cause of a superior orbital fissure syndrome. This mode of tumor spread, for which a previously excised invasive malignant tumor is responsible, is rarely reported. The absence of an intraorbital mass and the fact that computed tomography (CT) and magnetic resonance imaging (MRI) are normal make the diagnosis extremely difficult. We describe a 76-year-old patient in whom both intrane ural and perineural tumor growth deep into the orbit caused acute ocular motility disturbances, visual impairment, and ocular dysfunction with subsequent cerebral and vascular dysfunction. Surgery, radiotherapy, and orbital exenteration did not prevent spread of the tumor toward vital intracranial and intracerebral structures. Even the advanced diagnostic modalities of CT and MRI failed to reveal the cause of the pathologic process in our patient. In such a case, one should look carefully for both intraneural and perineural tumor invasion on previous histologic material and, if positive, treat the patient with radical surgery on purely clinical grounds as early as possible.