Probable IgG4-related pachymeningitis: a case with transverse sinus obliteration.

IgG4-related disease (IgG4-RD) is a recently recognized fibro-inflammatory condition which often shows a dramatic response to steroid therapy. IgG4-RD can present either as a single lesion or as a systemic multi-organ disorder. Common histological findings include a dense lymphoplasmacytic infiltrate rich in IgG4-positive plasma cells, storiform fibrosis, and phlebitis. Although diagnostic criteria for IgG4-RD have been proposed in many organs/sites, they are not well established in the central nervous system. Published data on IgG4-RD in meninges is also limited. To our knowledge, only 15 potential cases of meningeal IgG4-RD have been reported. We add a case of probable IgG4-related pachymeningitis in a 42-year-old woman who presented with headache and left transverse sinus obstruction. Follow-up after 2-months of high dose steroids shows dramatic clinical and imaging improvement. The differential diagnosis for IgG4-related pachymeningitis, including lymphoplasmacyte-rich meningioma, idiopathic hypertrophic pachymeningitis, and lymphoproliferative disease is discussed.