Bowen's disease clinically simulating an onychomatricoma.
Onychomatricoma (OM) is an uncommon benign tumor clinically characterized by a thickened yellowish nail with transverse over curvature. A pigmented variant has recently been described. Histologically, the diagnosis requires 3 prerequisites: (1) a fibroepithelial tumor consisting of 2 portions: the proximal zone (under the proximal nailfold, characterized by deep epithelial invaginations and a fibrillary and fibrocytic stroma), whereas the distal zone (corresponding to the lunula) presents with multiple digitations along its connective tissue axes; (2) a matricial tumor typified by a thick keratogenous zone; and (3) a thick nail plate, perforated by cavities. We describe a case that appears clinically identical to a pigmented OM, but with histologic malignant patterns. Because histologic features were consistent with Bowen's disease, we ruled out a malignant OM. We report a new variant of Bowen's disease presenting as OM, and this observation underlines the necessity for a histologic assessment of all forms of OM, especially those associated with a pigmented band (a sign sometimes observed in Bowen's disease).
Baran
Robert
R
Nail Disease Center, Cannes, France. baran.r@club-internet.fr
Perrin
Christophe
C
D000328:Adult; D001707:Biopsy, Needle; D001913:Bowen's Disease / Q000175:diagnosis / Q000473:pathology*; D003937:Diagnosis, Differential; D006801:Humans; D017495:Hyperpigmentation / Q000175:diagnosis / Q000473:pathology*; D007150:Immunohistochemistry; D008297:Male; D009260:Nail Diseases / Q000175:diagnosis / Q000473:pathology*