A long-term follow-up of necrobiotic xanthogranuloma with concomitant large-vessel vasculitis and heart failure with reduced ejection fraction: a case report

Necrobiotic xanthogranuloma (NXG) is a non-Langerhans cell histiocytosis and multisystem disorder. Low level of HDL cholesterol associated with a systemic inflammatory profile, which may result from the interaction of monoclonal immunoglobulin and lipoproteins, is a characteristic feature. There is no evidence of NXG-associated large-vessel vasculitis, nor are there any established treatments, although chemotherapy for comorbid multiple myeloma is most often administered.

We describe a case of a 53-year-old male with a first history of heart failure with impaired systolic function. He presented with orbital xanthomas and multiple subcutaneous nodules, and laboratory examination showed elevated levels of C-reactive protein, low HDL, and paraproteinemia. A constellation of these clinical features and pathological findings of skin biopsy led to the diagnosis of NXG. ¹⁸F-Fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) confirmed increased uptake in the aorta and bilateral common carotid arteries. He began prednisolone treatment with reference to treatment for large-vessel vasculitis. After the treatment, C-reactive protein immediately decreased with markedly increased levels of apolipoprotein A1 (Apo-A1) and HDL. Systolic dysfunction was restored at 6-month follow-up. The patient has not experienced heart failure for 5 years after treatment, and the follow-up PET/CT demonstrated resolution of vascular inflammation.

This is the first report of NXG-associated large-vessel vasculitis. Low-dose prednisolone may benefit for NXG-associated vasculitis and cardiomyopathy. HDL, Apo-A1, and C-reactive protein levels may be useful for monitoring the activity of NXG, and PET/CT was a valuable diagnostic tool for NXG-associated vasculitis.