Evaluation of the specificity of trigeminal nerve enlargement in the diagnosis of IgG4-related ophthalmic disease

Enlargement of the trigeminal nerve is observed in 20–53% of patients with IgG4-related ophthalmic disease (IgG4-ROD) and is known to be a useful finding for the diagnosis of IgG4-ROD. On the other hand, enlargement of the trigeminal nerve has also been found at a certain frequency in orbital lymphoproliferative diseases other than IgG4-ROD. Therefore, we here re-evaluated the specificity of trigeminal nerve enlargement in the diagnosis of IgG4-ROD.

Retrospective, comparative study.

A total of 149 consecutive cases of IgG4-ROD diagnosed at the Department of Ophthalmology, Tokyo Medical University Hospital were studied. As controls, 218 cases of orbital lymphoma, 13 cases of reactive lymphoid hyperplasia (RLH), and 117 cases of benign orbital tumors other than lymphoproliferative diseases were included. Enlargement of the trigeminal nerve (infraorbital or supraorbital nerve) in IgG4-ROD and all the control cases was evaluated on MRI or CT coronal images.

Enlargement of the trigeminal nerve was observed in 35 of the 149 cases (23.5%) of IgG4-ROD and in 7 of the 218 cases (3.2%) of lymphoma, with a significantly highly frequency in IgG4-ROD (P < .0001). No cases of trigeminal nerve enlargement were observed in the cases of RLH or benign orbital tumors. The sensitivity and the specificity of trigeminal nerve enlargement in the diagnosis of IgG4-ROD were 23.5% and 96.8%, respectively. Additionally, enlargement of the trigeminal nerve was significantly more common in men than in women (P < .028).

The present study indicates that trigeminal nerve enlargement is a characteristic imaging finding and has diagnostic value for IgG4-ROD.