Christophe Perrin1, Giuseppe Emilio Cannata, Lutz Langbein, Damien Ambrosetti, Michael Coutts, Thierry Balaguer, Jean-Marc Garzon, Jean-François Michiels. 1. *The Laboratoire Central d'Anatomie Pathologique, Hôpital L. Pasteur, University of Nice, Nice, France; †Nail's Dermatology Consultations, Cannes, France; ‡UOC Dermatologia, Ospedale Civile, Imperia, Italia; §Division of Genetic of Skin Carcinogenesis, Section of Normal and Neoplastic Epidermal Differentiation, German Cancer Research Center, Heidelberg, Germany; ¶Department of Pathology, West Kent Oncology Center, Maidstone Hospital, Hermitage Lane, England; ‖Service de Chirurgie Plastique, University of Nice, Nice, France; and **Institut Polyclinique de Cannes, Cannes, France.
Abstract
BACKGROUND: Besides onychomatricoma (OM), which shows a clinical band pattern of nail plate thickening, 2 new onychomatrical tumors with this clinical feature have recently been described: onychocytic matricoma (OCM) and in situ onychocytic carcinoma. OBJECTIVE: The purpose of this study was to present 4 cases of OCMs and compare their clinical and histopathologic characteristics with usual OMs. METHODS: We studied 4 cases of OCMs with nail clipping in 3 cases and an extensive immunohistochemical study for hair-related keratins and epithelial keratins. Nail clipping of OCMs was compared with the distal nail plate of 5 cases of OMs. RESULTS: All cases showed an acquired localized longitudinal band pattern of a thickened nail plate with yellow discoloration in 2 cases and a black streak in 2 cases. All cases showed a V-shaped keratogenous epithelial tumor with a papillomatous pattern of growth. The nail plate was thickened with small holes in a honeycomb pattern. In contrast, the 5 OMs showed the classical pattern of a panonychoma fibropapilliferum. The nail plate showed large cavities in a honeycomb pattern. CONCLUSIONS: This case series raises awareness of the clinical value of longitudinal pachyonychia coupled with nail clipping in the early detection of onychomatrical tumors as generic diagnosis with a limited differential diagnosis and a simple therapeutic approach. Nail clipping could be an aid in the surgical planning of onychomatrical tumor. A diagnosis of a benign growth could be suggested when the average dimensions of cavities are superior to 0.15 mm sparing the patient from an excisional procedure with its risk of subsequent permanent nail dystrophy. In contrast, nail clipping with a honeycomb pattern of minute cavities with average dimension inferior to 0.10 mm should prompt a biopsy of the distal matrix to rule out a malignant lesion.
BACKGROUND: Besides onychomatricoma (OM), which shows a clinical band pattern of nail plate thickening, 2 new onychomatrical tumors with this clinical feature have recently been described: onychocytic matricoma (OCM) and in situ onychocytic carcinoma. OBJECTIVE: The purpose of this study was to present 4 cases of OCMs and compare their clinical and histopathologic characteristics with usual OMs. METHODS: We studied 4 cases of OCMs with nail clipping in 3 cases and an extensive immunohistochemical study for hair-related keratins and epithelial keratins. Nail clipping of OCMs was compared with the distal nail plate of 5 cases of OMs. RESULTS: All cases showed an acquired localized longitudinal band pattern of a thickened nail plate with yellow discoloration in 2 cases and a black streak in 2 cases. All cases showed a V-shaped keratogenous epithelial tumor with a papillomatous pattern of growth. The nail plate was thickened with small holes in a honeycomb pattern. In contrast, the 5 OMs showed the classical pattern of a panonychoma fibropapilliferum. The nail plate showed large cavities in a honeycomb pattern. CONCLUSIONS: This case series raises awareness of the clinical value of longitudinal pachyonychia coupled with nail clipping in the early detection of onychomatrical tumors as generic diagnosis with a limited differential diagnosis and a simple therapeutic approach. Nail clipping could be an aid in the surgical planning of onychomatrical tumor. A diagnosis of a benign growth could be suggested when the average dimensions of cavities are superior to 0.15 mm sparing the patient from an excisional procedure with its risk of subsequent permanent nail dystrophy. In contrast, nail clipping with a honeycomb pattern of minute cavities with average dimension inferior to 0.10 mm should prompt a biopsy of the distal matrix to rule out a malignant lesion.