Multinodular hemosiderotic dermatofibroma.
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.
Requena
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Departamento de Dermatología, Hospital Universitario San Carlos, Facultad de Medicina, Universidad Complutense, Madrid, España.
Aguilar
A
A
López Redondo
M J
MJ
Schoendorff
C
C
Sánchez Yus
E
E
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*
D006485:Hemosiderin