Abstract: Objective To investigate the clinical characteristics and treatment of MPOANCA positive associated hypertrophic cranial pachymeningitis. Methods A case of MPOANCA positive hypertrophic cranial pachymeningitis with extensive pulmonary arterial thrombosis was reported and analyzed with the literature. Results The patient presented with impaired vision and headache. After admission，blood D-dimer 7. 09 mg/L FEU（ < 0. 5），ESR 33 mm/h（ < 15），anti-MPO antibody 137. 3 CU （ < 20. 0），anti-protease 3 antibody 22. 7 CU （ < 20. 0）. The three-dimensional CT scan of the mediastinum plus enhancement shows extensive thrombosis of both pulmonary arteries. Pulmonary artery CTA showed multiple pulmonary embolisms. Cerebral MRI showed in bilateral frontal-temporal dura thickening reinforcement，cavernous sinus，orbit，pharynx side clearance（right），and on the right side of the rock/article sinus flake reinforced under the shadow，and double side nerve local display was fine（right），the dura thickening of the skull base slightly obvious local/doubt slightly thick，diagnosis of MPO ANCA positive hypertrophic pachymeningitis，symptoms improved after immunization， anticoagulant therapy. Conclusion The clinical manifestations of MPO-ANCA positive hypertrophic cranial pachymeningitis are heterogeneous. Most patients have chronic headaches，with or without craniocerebral nerve palsy， cerebellar ataxia， epileptic seizure， myelopathy， visual impairment， and other neurological manifestations. In clinical practice，the possibility of MPO-ANCA positive hypertrophic cranial pachymeningitis should be considered in patients with headaches，multiple cranial nerve involvement，and sinusitis and otitis media.

Key words: hypertrophic cranial pachymeningitis, MPO-ANCA positive vasculitis, pulmonary artery thrombosis, case reports