title: Pseudoangiomatous xanthelasmoid mastocytosis: two case reports showing the hypervascularity of this rare variant of cutaneous mastocytosis.
abstract: Xanthelasmoid mastocytosis or xanthelasmoidea is a rare clinical variant of cutaneous mastocytosis characterized by a yellow hue of the clinical lesions, which are often misdiagnosed as juvenile xanthogranuloma. We present two pediatric cases of xanthelasmoid mastocytosis presenting as isolated mastocytomas, which are notable histopathologically for their hypervascularity. This pseudoangiomatous variant of cutaneous mastocytosis is important for pathologists to have knowledge of, so that a diagnosis of a vascular tumor is not rendered accidentally. The yellow hue has previously been explained by the usual deep and solid dermal mast cell infiltrate. In the two presented cases, however, the mast cell infiltrate was sparse, and the yellow color cannot be related to infiltrate density. We believe that the hypervascularity is at least one factor in the production of clinical xanthelasmoid appearance, and we propose the term 'pseudoangiomatous xanthelasmoid mastocytosis' to properly describe this rare variant of cutaneous mastocytosis.
authors.affiliation: Department of Dermatology and Dermatopathology, Saint-Pierre, Brugmann and HUDERF Hospitals, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Athanassios
authors.initials: A
authors.lastname: Kolivras
authors.affiliation: Department of Dermatology and Dermatopathology, Saint-Pierre, Brugmann and HUDERF Hospitals, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Josette
authors.initials: J
authors.lastname: André
authors.affiliation: Department of Biomedical Engineering, Oregon Health Sciences University, Portland, OR, USA.|Department of Pathology, Oregon Health Sciences University, Portland, OR, USA.|Department of Dermatology, Oregon Health Sciences University, Portland, OR, USA.
authors.forename: Curtis
authors.initials: C
authors.lastname: Thompson
authors.affiliation: Department of Dermatology and Dermatopathology, Saint-Pierre, Brugmann and HUDERF Hospitals, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Ursula
authors.initials: U
authors.lastname: Sass
authors.affiliation: Department of Pathology, hôpital Necker-Enfants Malades, APHP, Paris, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Fraitag
mesh_terms: D002648:Child; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D054705:Mastocytoma, Skin / Q000098:blood supply / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology; D014972:Xanthogranuloma, Juvenile / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology
keywords: hypervascularity; mastocytosis; vascular tumor