IgG4-related intracranial disease

Area of Science:

• Neurology
• Immunology
• Pathology

Background:

• Immunoglobulin G4-related disease (IgG4-RD) is a systemic fibroinflammatory condition characterized by IgG4-positive plasma cell infiltration.
• Intracranial manifestations of IgG4-RD are increasingly recognized but present with diverse clinical and imaging features.
• Accurate diagnosis of intracranial IgG4-RD is challenging due to its mimicry of other neoplastic and inflammatory conditions.

Observation:

• A case series of three patients with intracranial IgG4-RD is presented, highlighting varied presentations.
• Case 1: Mass-forming IgG4 pachymeningitis mimicking a sphenoid wing meningioma.
• Case 2: Extensive IgG4 pachymeningitis involving cavernous sinuses and Meckel's caves.
• Case 3: IgG4-related hypophysitis with concurrent pachymeningitis and optic nerve perineural spread.

Findings:

• Intracranial IgG4-RD can manifest as large mass-forming pachymeningitis, a presentation not previously described in such scale.
• IgG4-related hypophysitis can occur with contiguous spread, affecting cranial nerves.
• Diagnostic delays underscore the difficulty in differentiating IgG4-RD from conditions like sarcoidosis, lymphoma, and granulomatous diseases.

Implications:

• Earlier consideration of IgG4-related hypophysitis and hypertrophic pachymeningitis in the differential diagnosis is essential.
• Timely diagnosis can prevent significant patient morbidity, including unnecessary surgeries and organ failure due to fibrosis.
• This case series emphasizes the importance of recognizing the spectrum of intracranial IgG4-RD for improved patient outcomes.