title: Hobnail Hemangioma With an Unusual Clinical Presentation.
abstract: Hobnail hemangioma, also known as targetoid hemosiderotic hemangioma, is an uncommon vascular proliferation that clinically presents as a small solitary red to purple papule or macule, located on the limbs or trunk. Multiple lesions and atypical locations have been described. Histopathologically, it exhibits a biphasic pattern, with dilated vessels in the superficial dermis and angulated vessels in the deeper dermis, with endothelial cells that show a hobnail appearance. There is controversy about the histogenetic origin of hobnail hemangioma, although recent studies support that it is a lymphatic malformation. The investigators report the case of a 41-year-old man with an irregular lesion, red to purple in color, with a maximum diameter of 4 cm, on the scalp. The location and in particular the clinical appearance are uncommon. Immunohistochemical analysis showed negativity for WT1 and focal positivity for D2-40. Clinical-pathologic correlation acquires particular importance in the case of lesions with atypical clinical presentation.
authors.affiliation: 1 Department of Dermatology, Complejo Hospitalario Universitario de Granada, Spain.
authors.forename: María Librada
authors.initials: ML
authors.lastname: Porriño-Bustamante
authors.affiliation: 2 Department of Pathology, Complejo Hospitalario Universitario de Granada, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Aneiros-Fernández
authors.affiliation: 2 Department of Pathology, Complejo Hospitalario Universitario de Granada, Spain.
authors.forename: Juan Antonio
authors.initials: JA
authors.lastname: Retámero
authors.affiliation: 1 Department of Dermatology, Complejo Hospitalario Universitario de Granada, Spain.
authors.forename: María Antonia
authors.initials: MA
authors.lastname: Fernández-Pugnaire
mesh_terms: D000328:Adult; D006258:Head and Neck Neoplasms / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology*; D006391:Hemangioma / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology*; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis; D012535:Scalp; D012878:Skin Neoplasms / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology*; D025721:WT1 Proteins / Q000032:analysis; D000098853:Podoplanin
chemical_list: D008562:Membrane Glycoproteins; D025721:WT1 Proteins; C117468:PDPN protein, human; D000098853:Podoplanin; C583751:WT1 protein, human
keywords: hemangioma; hobnail cells; hobnail hemangioma; immunohistochemistry; pathology