Idiopathic myelofibrosis and pyoderma gangrenosum involving a mutation of janus kinase 2 (JAK2V617F), showing poor prognosis

摘要

A 74-year-old man had been treated for 2 years with oral prednisolone at 10 mg/day and warfarin for idiopathic myelofibrosis and temporal arteries, and deep vein thrombosis. A JAK2V617F mutation had also been identified. He noticed a hand-sized ulcer with bleeding, granulomatous papules on the back of the left leg and on the right lower thigh (figure 1A). At the same time, lower abdominal pain, severe diarrhoea, bloody stools and high fever appeared. A skin biopsy specimen from the ulcer showed numerous neutrophils, densely infiltrating with degeneration and necrosis of collagen fibres without vasculitis, from the upper dermis to the subcutaneous tissues. Cultures from skin biopsy specimens of the ulcer and from blood detected no pathogens. Laboratory examinations showed highly elevated levels of peripheral white blood cells (56,800/μL), neutrophils (54,500/μL), platelets (97.8 × 104/μL), and serum C-reactive protein levels (24.3 mg/dL). Serum MPO-ANCA and C-ANCA values were within normal limits. Colonoscopy revealed isolated, deeper linear and various sized ulcers in the sigmoid colon, compatible with ulcerative colitis. However, a biopsy specimen from the mucosal lesion could not be obtained because the patient was taking oral warfarin (figure 1B). Oral prednisolone was increased to 40 mg/day (1 mg/kg) for skin disease and inflammatory bowel disease, and intestinal symptoms and skin lesions improved within 1 month. Prednisolone was then successfully tapered to 10 mg/day without any recurrence of symptoms. However, he noticed dyspnoea and general malaise with high fever, and computed tomography of the chest demonstrated pneumonia of the right lower lung. A sputum culture yielded positive results for Enterococcus species. The pneumonia rapidly progressed despite administration of several kinds of antibiotics, and he died due to disseminated intravascular coagulation induced by sepsis.