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.