Idiopathic hypertrophic cranial pachymeningitis successfully treated with dexamethasone – a case report

Introduction :  Idiopathic hypertrophic cranial pachymeningitis (IHCP) is a rare pathological entity which is diagnosed after the exclusion of secondary reasons. Most frequently, IHCP is related to rheumatological diseases such as rheumatic arthritis, sarcoidosis, anti-neutrophil cytoplasmic antibody-associated vasculitis, and IgG4-related disorders. The inflammatory process concerns dura mater and manifests with symptoms of cranial nerve damage or compression. Case description :  A 59-year-old Caucasian man presented with transitional episodes of tinnitus and an unspecific headache. Imaging studies (magnetic resonance imaging – MRI) demonstrated a thickened dura mater. Lymphoma was suspected due to an abnormal flow cytometric analysis of a cerebrospinal fluid (CSF) sample. Hematological diagnostics including bone marrow biopsy, whole body computed tomography (CT) and digestion tract examination were performed leading to the exclusion of hematological malignancy. The patient underwent surgery, and a specimen from the lesion was obtained. On this basis, intracranial idiopathic hypertrophic pachymeningitis was diagnosed. First line treatment strategy was introduced with corticosteroids with a gradual dose reduction. After the 48-month follow-up, we observed an alleviation of symptoms with a gradual significant decrease in the thickening of dura matter with almost complete resolution. Conclusions :  Idiopathic hypertrophic pachymeningitis should be considered in the differential diagnosis of a thickened dura mater. Administration of steroids appears reasonable as a first line treatment of IHCP.