Purpose:

To describe the occurrence of multiple trigeminal nerves (TGNs) enlargement in patients with orbital IgG4-related disease.

Methods:

Retrospective review of MRI findings and medical records of 6 patients (10 orbits) with orbital IgG4-related disease and enlargement of more than 1 TGN. Orbital biopsies were performed in all cases revealing the typical lymphoplasmacytic infiltrate with significant plasma cell positivity for IgG4 (IgG4+/IgG ratio≥ 40%). Three experienced neuroradiologists reviewed the MRI sequences using a digital imaging viewer system (Horos, https://horosproject. org/).

Results:

Bilateral involvement of at least 2 TGNs divisions was detected in all 6 patients. Enlargement of both V1 and V2 nerves was diagnosed in 5 patients, and in 3 cases, all TGN divisions were involved. V2 nerves were the most affected. In this division, all 12 infraorbital nerves were enlarged, followed by lesser palatines (10/83.3%), superior alveolar (10/83.3%), and zygomatic (6/50%). V1 and V3 nerves were less affected albeit 9 (75%) frontal branches (V1), and 50% of the inferior alveolar (V3) nerves were also enlarged.

Conclusions:

Widespread involvement of the TGN is an important feature of IgG4-related disease.

In IgG4-related disease, any branch of the trigeminal nerve may be enlarged.

Enlargement of multiple branches of the trigeminal nerves (TGNs) is usually a sign of perineural spread of head and neck malignancies. 1 In 2011, Katsura et al. 2 reported a single patient with isolated enlargement of V2 and V3 branches who was diagnosed as having IgG4-related inflammatory pseudotumor of the TGN. Following this early report, Immunoglobulin G4-related disease (IgG4-RD) has been strongly associated with enlargement of the infraorbital nerve (ION). 3–17 The authors describe here a group of patients with IgG4-RD in whom several branches of the TGN were enlarged.

METHODS

This is a retrospective noncomparative analysis of the medical records of 6 patients who presented for assessment of orbital lesions and MRI evidence of trigeminal perineural disease. The study was approved by the institutional review board of the hospital and adhered to the tenets of the Declaration of Helsinki. Only patients with a biopsy-proven diagnosis of the orbital lesions and MRI imaging of both orbits and head were included. Diagnoses were based on the histopathologic characteristics of the tissue samples and on the results of immunohistochemical staining for IgG, IgG4, CD20, CD3, CD68, S100, and CD1A.