title: Multinodular hemosiderotic dermatofibroma.
abstract: We describe a patient who developed a pigmented plaque on the anterior aspect of his right knee clinically mimicking angiokeratoma circumscriptum or malignant melanoma. Histopathological examination demonstrated a multinodular hemosiderotic dermatofibroma in which the cellular tumor islands were separated by areas of hyalinized collagen. Multinucleated giant tumor cells were found in the lumen of a medium-size vein underlying the tumor. The differential diagnosis of angiomatoid malignant fibrous histiocytoma, a tumor with clinical and morphologic similarities, is discussed.
authors.affiliation: Departamento de Dermatología, Hospital Universitario San Carlos, Facultad de Medicina, Universidad Complutense, Madrid, España.
authors.forename: L
authors.initials: L
authors.lastname: Requena
authors.forename: A
authors.initials: A
authors.lastname: Aguilar
authors.forename: M J
authors.initials: MJ
authors.lastname: López Redondo
authors.forename: C
authors.initials: C
authors.lastname: Schoendorff
authors.forename: E
authors.initials: E
authors.lastname: Sánchez Yus
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D005350:Fibroma / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D006485:Hemosiderin / Q000032:analysis; D006801:Humans; D007717:Knee; D008297:Male; D010859:Pigmentation Disorders / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology; D012878:Skin Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*
chemical_list: D006485:Hemosiderin