Necrobiotic xanthogranuloma with monoclonal gammopathy of the IgG lambda type

A 77-year-old Swiss woman presented with a 25-year history of smoldering di sseminated normolipemic plane xanthomas confined to the neck and elbows acc ompanied by a monoclonal gammopathy of the IgG lambda type. There was a sud den onset of a progressive course with increase in number and size of infla mmatory lesions over the past year. The clinical and histological picture s upported the development into a necrobiotic xanthogranuloma (NXG). Skin les ions responded to therapy with low-dose melphalan. Our case supports the no tion that normolipemic plane xanthoma and NXG form a spectrum of xanthomato us dermal reactions with paraproteinemia.