Optic nerve biopsy via a medial transconjunctival orbitotomy approach in the diagnosis of optic nerve and sheath tumors.

PURPOSE

To evaluate the role of optic nerve biopsy in the diagnosis and management of optic nerve and sheath tumors.

METHODS

Seven patients with progressive optic nerve and sheath tumors for whom treatment was deemed necessary were included in this study. Optic nerve biopsy via a medial transconjunctival orbitotomy approach was performed in all patients

RESULTS

There were no complications related to the surgical procedure. Histopathological examination revealed that five patients had juvenile pilocytic astrocytoma (JPA) and two patients had optic nerve sheath meningioma (ONSM). All patients received external beam radiotherapy (EBRT).

CONCLUSIONS

Many other benign and malignant optic nerve and sheath tumors have imaging features similar to those seen in JPA and ONSM. Therefore, it is important to establish histopathologic diagnosis before embarking on treatment. Furthermore, tissue diagnosis is required prior to EBRT in many institutions because of concerns about medicolegal liability. Optic nerve biopsy via a transconjunctival orbitotomy procedure in seven patients yielded histopathologic confirmation of the existing pathology and was not associated with any complications in this series.