title: An unusual histologic variant of necrobiotic xanthogranuloma.
abstract: Necrobiotic xanthogranuloma (NXG) usually shows a stereotypical histopathologic presentation. However, few unusual cases have been published. We present a patient with NXG showing exceptional histopathologic features. NXG in our patient presents with exclusively dermal granulomatous inflammation mimicking interstitial granuloma annulare. Not only subcutaneous involvement, but also, evident zones of degenerated collagen, foam cells, and cholesterol clefts were missing. Moreover, the case shows overlaps with recently published granulomatous scleromyxedema. Some common clinical and histopathologic features of NXG and scleromyxedema might be based on shared underlying paraproteinemia.
authors.affiliation: Department of Dermatology, Venereology, and Allergology, University Hospital of Leipzig, Philipp-Rosenthal-Str. 23–25, Leipzig, Germany. mirjana.ziemer@medizin.uni-leipzig.de
authors.forename: Mirjana
authors.initials: M
authors.lastname: Ziemer
authors.forename: Johannes
authors.initials: J
authors.lastname: Norgauer
authors.forename: Jan-Christoph
authors.initials: JC
authors.lastname: Simon
authors.forename: Martin Johannes
authors.initials: MJ
authors.lastname: Koehler
mesh_terms: D005260:Female; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use; D008875:Middle Aged; D008998:Monoclonal Gammopathy of Undetermined Significance / Q000150:complications; D058252:Necrobiotic Xanthogranuloma / Q000150:complications / Q000188:drug therapy / Q000473:pathology*
chemical_list: D016756:Immunoglobulins, Intravenous