[Systemic necrotizing vasculitis presenting as gangrene combined with diabetes insipidus: a case report]

The male patient reported here presented as gangrene and central diabetes insipidus (CDI), who had characteristics of vasculitis. The patient complained about polydipsia and polyuria half a year ago, and then developed tingling, pain and blackish discoloration of some fingers and toes 3 month ago. He also had Raynaud's phenomenon. After admission, his laboratory examination showed the rise of erythrocyte sedimentation rate, C-reactive protein, immunoglobulin, β2-glycoprotein I and the activity of rheumatoid factors, lupus anticoagulant test. his pituitary gland showed loss of posterior signal on magnetic resonance imaging. In addition, his vasopressin test was active. However, there was no sufficient evidence to diagnose any specific disease; as a consequence the patient was diagnosed as idiopathic systemic necrotizing vasculitis (SNV). For SNV, the patient was treated with glucocorticoid 40 mg/d and impact therapy of cyclophosphamide 0.4 g every 2 weeks. He also received symptomatic treatment for gangrene and CDI. Cutaneous involvement leading to gangrene was widely reported in SNV, however pituitary involvement in SNV leading to CDI was rare. The prognosis of this patient was poor.