Prompted by a recurring skull base multidisciplinary team debate on the necessity of securing a definitive tissue diagnosis before initiating treatment for lesions of the orbital apex, a review of anterior skull base procedures over an 11-year period was undertaken.

Data collected prospectively on cases from 2006 to 2017 were analysed. Presenting symptoms, imaging and histology findings, outcomes, complications, and impact on treatment were evaluated. All surgery was carried out endoscopically with the aid of image guidance.

Twenty-one patients undergoing endoscopic orbital apex and/or optic canal biopsy were included. The mean patient age was 49 years. Five malignant tumours were identified, five benign tumours, seven infective cases (two tuberculosis and five fungal) and two cases of immunoglobulin G4 related disease. Two patients had non-diagnostic biopsies (one lesional) and were treated successfully as Tolosa–Hunt syndrome cases.

A successful diagnosis was achieved in nearly all cases without adverse impact, other than one cerebrospinal fluid leakage case. Management was directly influenced by the outcome in all cases.

Tolosa–Hunt syndrome is a rare condition of painful ophthalmoplegia combined with ipsilateral ocular motor nerve palsies, caused by non-specific granulomatous inflammation in the cavernous sinus, superior orbital fissure or orbit. A case of Tolosa–Hunt syndrome misdiagnosed as sinusitis orbital complication is reported.

A patient suffering from left periorbital pain, upper eyelid oedema and ptosis, and horizontal diplopia, diagnosed as sinusitis orbital complication, was referred to our department. Clinical evaluation revealed only a left VIth nerve paresis. Haematological studies, cerebrospinal fluid tests and computed tomography scanning were negative. A magnetic resonance imaging (MRI) scan showed enhancement of the left cavernous sinus. Corticosteroid therapy was commenced, and within three days all symptoms disappeared. A diagnosis of Tolosa–Hunt syndrome was made. Follow-up MRI studies were normal.

Tolosa–Hunt syndrome, although rare, is a nosological entity that otolaryngologists must bear in mind. Magnetic resonance imaging studies are essential in the diagnosis and follow up of these patients, in order to avoid a mistaken Tolosa–Hunt syndrome diagnosis.