A 52-year-old woman referred to our skin cancer unit for the presence of yellow periorbital plaques that enlarged over the past decade. Based on the clinical and dermoscopic presentations ( Figure 1 ), a clinical diagnosis of necrobiotic xanthogranuloma (NX) was suspected. A full laboratory workup was performed including skin and bone marrow biopsy, CT scan of the orbital region and urine examination. Tests revealed an IgG paraproteinemia without bone involvement and, based on skin biopsy, the diagnosis of NX BRAF wild type was confirmed.
Figure 1 .
(A) Clinical appearance of necrobiotic xanthogranuloma showing eyelid and periorbital yellow plaques. (B) Dermoscopic features of XN showing yellow structureless areas that correspond to the presence of histiocytes in the dermis. (C) H&E histological detail showing foamy histiocytes in the dermis.
Necrobiotic xanthogranuloma is a rare manifestation of non-Langerhans histiocytosis and it is often associated with monoclonal gammopathy.