IgG4-related idiopathic hypertrophic pachymeningitis: one case report and review of the literature

Objective To study the clinical, neuroimaging and histopathological features of IgG4-related idiopathic hypertrophic pachymeningitis (IHP). Methods One case of pathologically confirmed IgG4-related IHP was reported, and related literature of the clinical, radiological and pathological characteristics of this disease was reviewed. Postoperative specimen was sent to Department of Pathology, Xuanwu Hospital. It was sliced and then stained with HE method and examined by immunohistochemistrical study (S-100, Ki-67, CD20, CD3, IgG, IgG4). Results The case was a 55-year-old male patient with IHP. The clinical manifestations of IHP were variable. The patient firstly presented seizures of epilepsy showing left limb convulsions. Brain contrast-enhanced MRI showed that the pachymenx was partly thickened with line-like or nodular enhancement. Microscopically, meningeal biopsies showed dura mater encephali was thickened and hardened. Under microscope, meningeal biopsies showed abnormal thickening of the pachymenx with fibrous connective tissue hyperplasia and infiltration of many inflammatory cells. Inflammatory cells were mainly composed of lymphocytes and plasmocytes with a small amount of eosinophils. Immunohistochemistrical study showed a large number of lymphocytes with expression of IgG, and a small part with expression of IgG4. The treatment of IgG4-related IHP with hormones and immunosuppressive agents was effective. Conclusion IHP is a class of unknown etiologic diseases, with dural fibrous inflammatory lesion, and part of the IHP patients may be suffering from IgG4-related IHP. DOI：10.3969/j.issn.1672-6731.2011.05.01