A case of slowly progressive type 1 diabetes mellitus developing myeloperoxidase-specific anti-neutrophil cytoplasmic antibody-associated vasculitis with hypertrophic pachymeningitis manifesting as multiple cranial nerve palsy

We report a 63-year-old man with a 35-year history of slowly progressive type 1 diabetes mellitus (SPIDDM), complicated with myeloperoxidase-specific anti-neutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitis presenting alveolar hemorrhage and pachymeningitis. The patient was first diagnosed as having DM at age of 28 years old and deteriorated secretion of insulin and the typical clinical course led us to the diagnosis of SPIDDM. When he was 58 years old, he suffered from fever, headache, and alveolar hemorrhage. He was diagnosed as having MPO-ANCA associated vasculitis based on a high titer of MPO-ANCA and histological findings of lung biopsy. Treatment with steroid pulse therapy, followed by oral prednisolone and oral cyclophosohamide, resulted in clinical improvement. Five years later, he complained of double vision. A gadolinium-enhanced magnetic resonance imaging (MRI) study of the brain showed normal. Two months later, he developed right cranial nerve V~XII palsy. A second MRI study revealed thickening of the right temporal region and cerebellar dura mater, leading us to the diagnosis of hypertrophic pachymeningitis. He responded well to oral prednisolone (50 mg/day) and intravenous cyclophosohamide (500 mg). This is the first case report of SPIDDM complicated with MPO-ANCA-associated vasculitis, manifesting as alveolar hemorrhage and hypertrophic pachymeningitis.