IgG4-related pachyleptomeningitis with inflammatory pseudotumor

Area of Science:

• Neurology
• Immunology
• Pathology

Background:

• IgG4-related disease (IgG4-RD) is a multisystem fibroinflammatory condition.
• Pachyleptomeningitis, inflammation of the dura and pia mater, can have various causes.
• IgG4-related pachyleptomeningitis has not been previously documented.

Purpose of the Study:

• To report the first case of IgG4-related pachyleptomeningitis.
• To describe the clinical and pathological features of this rare condition.
• To explore the potential pathogenesis linking dural pseudotumors and meningeal inflammation.

Main Methods:

• Case presentation and detailed clinical history.
• Neuroimaging (MRI) to assess dural and meningeal involvement.
• Histopathological examination of affected meningeal and dural tissues.
• Immunohistochemical analysis for IgG4-positive plasma cells.

Main Results:

• The patient presented with symptoms suggestive of meningeal irritation.
• Neuroimaging revealed pachymeningeal thickening and an ipsilateral inflammatory pseudotumor.
• Histopathology confirmed IgG4-related inflammation in the meninges and pseudotumor, characterized by abundant IgG4-positive plasma cells and fibrosis.

Conclusions:

• This is the first reported case of IgG4-related pachyleptomeningitis.
• The findings suggest that inflammation from a dural pseudotumor may spread to adjacent meninges, causing IgG4-related pachyleptomeningitis.
• This case expands the spectrum of IgG4-related disease manifestations and highlights the importance of considering IgG4-RD in cases of unexplained pachymeningitis and dural masses.