title: Cutaneous epithelioid cell histiocytoma: immunohistochemical and ultrastructural findings suggesting endothelial origin.
abstract: A 13-year-old boy presented with a polypoid nodule localized in the groin. Although the clinical and histopathological features corresponded to previously described diagnostic criteria of epithelioid cell histiocytoma, immunohistochemical and ultrastructural findings suggested vascular differentiation of the epithelioid cells. In particular, the immunohistochemical negativity of the epithelioid cell elements for Factor XIIIa failed to substantiate the previously forwarded hypothesis that this lesion represents a dendrocytoma. Instead, the presence of histiocytoid, vacuolated cells occasionally containing sparse red blood cells, positive staining for Factor VIII-related antigen, and ultrastructural evidence of endothelial characteristics in epithelioid neoplastic cells favor the hypothesis that "epithelioid cell histiocytoma" is of endothelial origin. We suggest the descriptive term cutaneous histiocytoid hemangioendothelioma for this lesion.
authors.affiliation: Department of Dermatology, University of L'Aquila, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Manente
authors.forename: I
authors.initials: I
authors.lastname: Schmitt
authors.forename: A M
authors.initials: AM
authors.lastname: Onetti
authors.forename: K
authors.initials: K
authors.lastname: Peris
authors.forename: E
authors.initials: E
authors.lastname: Caracciolo
authors.forename: S
authors.initials: S
authors.lastname: Chimenti
mesh_terms: D000293:Adolescent; D014408:Biomarkers, Tumor / Q000032:analysis; D002454:Cell Differentiation; D019070:Cell Lineage; D004730:Endothelium, Vascular / Q000473:pathology* / Q000648:ultrastructure; D015622:Epithelioid Cells / Q000473:pathology* / Q000648:ultrastructure; D004912:Erythrocytes / Q000473:pathology; D006119:Groin; D006390:Hemangioendothelioma / Q000473:pathology; D006644:Histiocytes / Q000473:pathology; D018219:Histiocytoma, Benign Fibrous / Q000473:pathology* / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D011127:Polyps / Q000473:pathology; D012878:Skin Neoplasms / Q000473:pathology* / Q000648:ultrastructure; D011503:Transglutaminases / Q000032:analysis; D014617:Vacuoles / Q000648:ultrastructure; D014841:von Willebrand Factor / Q000032:analysis
chemical_list: D014408:Biomarkers, Tumor; D014841:von Willebrand Factor; D011503:Transglutaminases