Background: Subungual squamous cell carcinoma (SSCC) is the most frequent tumor of the nail apparatus. Its diagnosis is often missed or delayed because the clinical presentation is atypical and can mimic other conditions. Accurate diagnosis can only be made by performing an appropriate surgical biopsy, but biopsy is painful and often leaves definitive dystrophic scars. Read More
Onychomatricoma is a rare benign neoplasm of the nail matrix first described by Baran and Kint in 1992. Fewer than 80 cases of onychomatricoma have been described in the literature, 15 of which were initially misdiagnosed and treated as onychomycosis. We present the case of a 66-year-old male with thickening and linear xanthonychia of the hallux nail plate secondary to an onychomatricoma misdiagnosed as onychomycosis. Read More
Onychomatricoma is a rare benign tumour of the nail matrix first described in 1992, and since then, no more than 80 cases have been reported. Despite distinct clinical characteristics, it is frequently misdiagnosed as onychomycosis partly due to remaining an unknown entity. The authors present the case of a patient with a 30-year history of nail abnormalities with more recent growth to alarming dimensions. Read More
The nail apparatus is an integral part of the functional unit of the digital tip. Although overall uncommon, all cells and tissues occurring in this area can give rise to neoplastic lesions. Given the special anatomical location, such tumors frequently show morphological and symptom-related differences compared to similar lesions located elsewhere on the skin. Read More
Onychomatricoma (OM) presenting as a longitudinal melanonychia is a very uncommon clinical presentation with very few cases in the literature. Our aim in this article is to report four cases of pigmented OM, and describe their clinical and dermoscopic findings and the importance of the differential diagnoses, especially with melanoma. Read More
The authors present a 43-year-old woman with a yellow, swollen toe nail of the right foot. This nail was lesioned 20 years before. The proximal nail fold of the right hallux was erythematous and indurated. Read More
Background: Amelanotic nail tumours are difficult to diagnose. Dermoscopy is an accessible tool successfully used in diagnosis of amelanotic or melanotic skin tumours. We have previously shown the usefulness of dermoscopy in the preoperative diagnosis of onychomatricoma (OM). Read More
Onychocytic matricoma (OCM) is a benign tumor of adnexal keratinocytes in which there is complete cytodifferentiation toward the germinative cells of the nail matrix, the keratogenous zone cells, and cells of the nail plate. Several microscopic variants of OCM were initially recognized; acanthotic type, acanthotic and papillomatous type, keratogenous type, and melanocytic as slight proliferation of dendritic melanocytes within the basaloid cells. This study reports an additional histopathologic variant of OCM. Read More
The authors present a case of onychomatricoma, a rare benign tumour of the nail matrix, first described by Baran and Kint in 1992. The lesion appeared on the proximal nail fold, covering half the nail of the second left finger. The nail was thickened and yellowish with longitudinal melanonychia. Read More
Onychomatricoma is a rare benign fibroepithelial tumour that originates from the nail matrix and can affect the nail bed of fingers and toes. Onychomatricoma may represent a premalignant lesion and although the etiology is still not fully understood, a previous finger trauma is considered the main predisposing factor. Unlike previous scientific articles we report a case of a "non traumatic" onychomatricoma in a 60 years old woman underlining the clinical and histological features to distinguish this uncommon lesion from other lesions originating from the nail apparatus. Read More
Onychomatricoma is a rare and benign tumour of the nail matrix but originates rarely from the ventral portion of the proximal nail fold. This tumour is characterised by fingerlike projections that invade the nail plate. This lesion, of unknown aetiology, is typically asymptomatic with slow progression. Read More
Nail dermoscopy is helpful in the differential diagnosis of nail disorders including onychomycosis and pigmented and nonpigmented nail tumors. We report two cases of onychomatricoma with concurrent onychomycosis of the same digit. In both cases, dermoscopy of the nail plate exhibited features of onychomatricoma, whereas dermoscopy of the distal free edge revealed features of onychomycosis. Read More
Onychomatricoma is a rare benign fibroepithelial filamentous tumor originating from the nail matrix. It typically presents with the clinical tetrad of xanthonychia, pachyonychia, proximal splinter hemorrhages and increased transverse overcurvature of the nail plate. The giant variant can easily confuse the clinician due to its extensive nail dystrophy that can mask the characteristic features of this tumor. Read More
*Laboratoire Central d'Anatomie Pathologique, Hôpital L. Pasteur,University of Nice, France; †Nail's Dermatology Consultations, Cannes, France; ‡UOC Dermatologia, Ospedale Civile, Imperia, Italia; and §Division of Genetic of Skin Carcinogenesis, Section of Normal and Neoplastic Epidermal Differentiation, German Cancer Research Center, Heidelberg, Germany.
The authors have recently proposed to use the name pachyonychia as an umbrella term that includes 2 distinctly different entities in the form of congenital pachyonychia and acquired longitudinal pachyonychia. Congenital pachyonychia is defined by a diffuse hyperkeratosis of the nail bed. Acquired longitudinal pachyonychia correspond to the true definition of pachyonychia, that is, a thickened nail plate without subungual keratosis. Read More
Onychomatricoma (OM) is a rare tumor originating from the nail matrix. Fingernail involvement is twice as common as toenail involvement. Onychomatricoma is the only tumor that actively produces a nail plate. Read More
Onychomatricoma is a rare tumor of the nail matrix. Until now, few cases of onychomatricoma have been reported in the literature. Immunohistochemically, CD10, a marker of the onychodermis, is expressed in the stroma of the onychomatricoma. Read More
*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.
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. Read More
Giant onychomatricoma is a rare fibroepithelial nail matrix tumor with only two previous reports in literature, from Mexico. An 80-year-old female patient presented with a progressively painless mass in the left great toe nail, following trauma, of 2 years duration. On examination there was a single, hard, immobile mass of size 4 × 3 × 2 cm with proximal hyperpigmentation of the left great toe nail. Read More
Onychomatricoma is a subungual tumor that is clinically characterized by banded or diffuse thickening, yellowish discoloration, splinter hemorrhages, and transverse overcurvature of the nail plate. It is often and easily misdiagnosed because the condition is not well known and rarely has been described. We report the case of a 45-year-old man with a subungual tumor on the right index finger that fulfills the criteria of onychomatricoma. Read More
Background: Onychomatricoma is a benign tumor of the nail matrix with a precise histopathological definition but many different clinical features and differential diagnoses.
Objectives: The diagnosis of onychomatricoma is based on the pathological examination of a surgical specimen. The objective of this study was to define preoperative diagnostic criteria using noninvasive investigations: observation and dermoscopy. Read More
Section of Dermatology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia The Skin Surgery Centre, Metairie, Louisiana Section of Dermatology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia.
A sixty-one year old white female was referred to the Dermatology Department to treat an ingrown nail in the inner corner of the left hallux. Examination of the entire nail unit showed the presence of xanthonychia in the outer corner besides thickening and increase in the transverse curvature of the nail plate. Dermoscopy and nuclear magnetic resonance of the free edge of the nail plate detected characteristic signs of onychomatricoma, a diagnosis that was later confirmed by anatomopathological exam. Read More
A 57-year-old woman presented with a 3-year history of a thickened, yellowed, over-curved nail plate of the left second toe. The proximal nail fold had an associated nodule. When observed head-on, the distal nail plate demonstrated multiple circular perforations. Read More
Dermatol Clin 2015 Apr 24;33(2):289-301. Epub 2015 Feb 24.
Department of Dermatology, Hospital of the University of Pennsylvania, 3600 Spruce Street, 2 Maloney, Philadelphia, PA 19104, USA; The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
"Nail clipping is a simple technique for diagnosis of several nail unit dermatoses. This article summarizes the practical approach, utility, and histologic findings of a nail clipping in evaluation of onychomycosis, nail unit psoriasis, onychomatricoma, subungual hematoma, melanonychia, and nail cosmetics, and the forensic applications of this easily obtained specimen. It reviews important considerations in optimizing specimen collection, processing methods, and efficacy of special stains in several clinical contexts. Read More
This article reviews 6 nail disorders that, although easy to diagnose, are misdiagnosed frequently by dermatologists and general practitioners. Diagnostic clues are emphasized to familiarize readers with features that indicate the correct diagnosis. We focus on two common tumors (onychomatricoma and onychopapilloma), two rare genetic conditions that can be diagnosed owing to nail changes (Darier disease and nail patella syndrome), and two uncommon acquired disorders (the yellow nail syndrome and lichen striatus). Read More
Onychomatricoma is a tumor of the nail matrix which often presents with alterations in the nail plate while the tumor itself is concealed beneath the nail plate. It is a benign, biphasic fibroepithelial tumor which has to be differentiated from other subungual and periungual tumors. We report a rare case of onychomatricoma and describe a three-dimensional histopathological analysis and immunohistochemical patterns of onychomatricoma. Read More
Neoplasms originating from nail matrix keratinocytes are very rare. Onychomatricoma and onychocytic matricoma are benign tumors arising from nail matrix keratinocytes. Only one case of onychocytic carcinoma, the malignant counterpart of onychocytic matricoma, has been reported in the literature. Read More
Onychomatricoma and glomus tumor are two rare subungual neoplasms with distinct clinical and histopathological features. We report a case of onychomatricoma associated with a glomus tumor in the subungual region of the same finger in a 45-year-old woman. Histopathological examination revealed characteristic findings of both onychomatricoma and glomus tumor. Read More
Pigmented onychomatricoma is a rare nail unit tumor that can clinically mimic nail unit melanoma. We report the case of a 63-year-old male with new-onset longitudinal melanonychia involving his right second toe. An excisional biopsy was performed and demonstrated pigmented onychomatricoma. Read More
Onychomatricoma is a rare tumor originating from the nail matrix, and, in rare conditions, from the ventral aspect of the proximal nailfold. Here we report a rare case of a 51-year-old man presenting with melanonychia mainly involving the distal nail plate. Histopathologic examination showed typical findings of onychomatricoma mainly involving the nail bed, while the nail matrix was largely uninvolved. Read More
β-catenin plays an important role in hair morphogenesis. Previously, the nuclear and cytoplasmic localizations of β-catenin were identified in hair-matrix cells. To evaluate β-catenin expression in the nail matrix, we obtained human nail units. Read More
Onychomatricoma is a benign slow-growing fibroepithelial tumor arising from the nail matrix. The tumor was described as a new entity almost two decades ago. Although the clinical appearance is typical, most cases are probably misdiagnosed by physicians because of unfamiliarity with the condition. Read More
Background: Onychomatricoma is a benign fibroepithelial nail matrix tumor that infiltrates the nail plate leading to multiple tunneled cavities lined with matrix epithelium and filled with serum. Diagnostic features of onychomatricoma on reflectance confocal microscopy (RCM) have not been previously described.
Objective: We sought to demonstrate the feasibility of using RCM to diagnose onychomatricoma. Read More
Department of Dermatology, University Hospitals Brugmann, St Pierre and Queen Fabiola's Children Hospital, Université Libre de Bruxelles, CHU Saint Pierre, Rue Haute 322, 1000 Brussels, Belgium. Electronic address:
Most neoplasms of the nail apparatus have different clinical appearances, courses, and biological behaviors as compared with similar tumors located elsewhere on the skin. Some of these tumors are unique to the nail, such as onychomatricoma. As a general rule, benign lesions respect the general architecture of the nail apparatus, whereas malignant ones are destructive. Read More
This second part of the review categorizes the site-specific nail tumors, as proposed in the first part, according to their clinical presentations. Acquired localized longitudinal pachyonychia allows for the specific recognition of onychogenic nail tumor, which can be classified into 2 groups according to the predominant compartment of origin within the nail unit as follows: epithelial tumors encompassing onychocytic matricoma and onychocytic carcinoma, and fibroepithelial tumors: the so-called onychomatricoma. As onychomatricoma is neither an epithelial matrical tumor nor a tumor with a limited differentiation toward the matrix, the author proposes instead the descriptive term of panonychoma fibropapilliferum (POP). Read More
The article aims to be a guide to the interpretation of tumors specific to the nail, that is, tumors presenting peculiar histological features linked specifically to the nail unit. Therefore, the classical epithelial, fibroepithelial, and fibrous skin tumors occurring in the nail region are not analyzed. The interpretation of nail biopsies requires the identification and integration of the 2 main clinical modes of presentation of nail tumors, the acquired localized (monodactylous) longitudinal (ALL) band pattern, and the "masked" nail tumor. Read More
Onychocytic matricoma is a newly described matrical tumor of the nail unit that clinically presents with localized thickening of the nail plate and melanonychia and represents a benign acanthoma of onychocytes. Onychocytic matricoma can be classified according to its histopathologic type (acanthotic, papillomatous or keratogenous with retarded maturation) and pigmentation (pigmented, melanocytic or non-pigmented). However, there are no published reports of non-pigmented onychocytic matricoma. Read More