Abstract: Objective:To determine the clinical,pathological and radiological features of hypertrophic cranial pachymeningitis (HCP).Methods:The clinical data of 5 patients with HCP were studied retrospectively,and the literature was reviewed.Results:All the 5 patients presented the symptom of headache.Two of them were accompanied by language barriers,1 by limb convulsion,reaction slowness,cranial nerve damage and walking instability,and 1 by memory impairment.MRI scan showed that 2 cases displayed edema changes within the brain parenchyma,and there was a wide range of enhanced thickening in all the 5 cases after enhancement,particularly at the frontal and top of the dura mater,the falx and the tentorium.The brain biopsy of 1 patient showed that the dura mater was significantly thickened,and the dural fibrosis pathology indicated the existence of a large number of plasma cell,lymphocyte,macrophage,neutrophil infiltration and focal calcification,which was considered to be a non-specific chronic inflammation.The brain blood vessels under the dura mater were dilated,with plasma cell and macrophage infiltration.The corresponding brain parenchyma also displayed non-specific inflammatory changes.Conclusions:Causes of HCP are complicated.The common clinical manifestations include headache,body convulsion,reaction slowness,speech impairment,memory impairment,walking instability and cranial nerve damage;Pathology showed dural fibrosis and inflammatory cell infiltration;the corresponding parts of the brain parenchyma may also display non-specific inflammatory changes,and such typical changes in head MRI enhanced imaging is beneficial to clinical diagnosis.