Idiopathic hypertrophic pachymeningitis mimicking prolactinoma with recurrent vision loss

Idiopathic hypertrophic pachymeningitis in a patient with a history of diffuse large B cell lymphoma

A man in his early 70s with a 4-year history of diffuse large B cell lymphoma (DLBCL) was admitted to our hospital with diplopia and achromatopsia. Neurological examination revealed visual impairment, ocular motility disorder and diplopia on looking to the left. Blood and cerebrospinal fluid investigations showed no significant findings. MRI revealed diffusely thickened dura mater and contrast-enhanced structures in the left apical orbit, consistent with hypertrophic pachymeningitis (HP). We performed an open dural biopsy to distinguish the diagnosis from lymphoma. The pathological diagnosis was idiopathic HP, and DLBCL recurrence was ruled out. Following methylprednisolone pulse and oral prednisolone therapy, his neurological abnormalities gradually receded. Open dural biopsy played an important role not only in diagnosing idiopathic HP but also in relieving the pressure on the optic nerve.

Idiopathic Hypertrophic Pachymeningitis Mimicking Meningioma with Occlusion of Superior Sagittal Sinus: Case Report and Review of Literature

BACKGROUND

Idiopathic hypertrophic pachymeningitis is a rare inflammatory condition with diffuse thickening of the dura mater, which may cause a compressive effect or vascular compromise.

CASE DESCRIPTION

A 40-year-old Chinese man presented with persistent headache for 6 months and a sudden epileptic seizure 2 days ago. Magnetic resonance imaging demonstrated a large (71 × 34 × 27 mm) extra-axial mass at the right frontal convexity with severe edema mimicking meningioma. The lesion and peripheral dura mater showed contrast enhancement. Additionally, the skull near the lesion was eroded. Meningioma was diagnosed, and the patient underwent surgery. During the operation, we found the lesion texture was very tough, and the superior sagittal sinus was occluded. Histopathologic findings revealed a large number of infiltrated lymphocytes with fibrosis and microabscess formation; intracranial idiopathic hypertrophic pachymeningitis was diagnosed. Follow-up magnetic resonance imaging performed 3 months after surgery demonstrated the enhancement was notably alleviated.

CONCLUSIONS

Idiopathic hypertrophic pachymeningitis should be part of the differential diagnosis of some cases of meningioma.