title: Onychocytic carcinoma: a new entity.
abstract: We have recently described a new nail tumor known as onychocytic matricoma. Herein, we describe its malignant counterpart. Clinically, the tumor simulates onychomatricoma (OM). Histologically, this in situ malignant epithelial tumor exhibits a distinct picture of onychocytic differentiation with signs of both nail matrical differentiation and nail plate differentiation. We have proposed the name onychocytic carcinoma for this singular adnexal neoplasm. Given the peculiar thickening of the nail plate observed in OM, onychocytic matricoma, and onychocytic carcinoma, the clinical individualization of a new type of nail band pattern could be proposed. It presents as an acquired localized (monodactylous) longitudinal pachyonychia. Such longitudinal pachyonychia allow the recognition of the matrical nail tumor, which has a limited etiological spectrum. Xantholeucopachyonychia suggests mainly OM and rarely onychocytic carcinoma. Pachymelanonychia suggests onychocytic matricoma and rarely pigmented OM or onychocytic carcinoma.
authors.affiliation: Laboratoire Central d'Anatomie Pathologique, Hôpital Pasteur, University of Nice, Nice, France. xst.perrin @bbox.fr
authors.forename: Christophe
authors.initials: C
authors.lastname: Perrin
authors.forename: Lutz
authors.initials: L
authors.lastname: Langbein
authors.forename: Damien
authors.initials: D
authors.lastname: Ambrossetti
authors.forename: Nouran
authors.initials: N
authors.lastname: Erfan
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schweizer
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Michiels
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D001706:Biopsy; D002277:Carcinoma / Q000737:chemistry / Q000145:classification* / Q000473:pathology; D002454:Cell Differentiation; D005385:Fingers; D006801:Humans; D007150:Immunohistochemistry; D053564:Keratins, Hair-Specific / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009260:Nail Diseases / Q000145:classification* / Q000378:metabolism / Q000473:pathology; D009262:Nails / Q000737:chemistry / Q000473:pathology*; D011237:Predictive Value of Tests; D012878:Skin Neoplasms / Q000737:chemistry / Q000145:classification* / Q000473:pathology; D009626:Terminology as Topic
chemical_list: D014408:Biomarkers, Tumor; D053564:Keratins, Hair-Specific