BMJ Case Rep 2017 Apr 21;2017. Epub 2017 Apr 21.

Department of Dermatology, Hospital Garcia de Orta, Almada, Portugal.

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

J Dtsch Dermatol Ges 2017 Apr;15(4):367-386

Department of Dermatology, Inselspital, University of Bern, Bern, Switzerland.

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

Australas J Dermatol 2017 Mar 23. Epub 2017 Mar 23.

Dermatology Department, Municipal Public Hospital of São Paulo, São Paulo, Brazil.

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

Ned Tijdschr Geneeskd 2017 ;161(0):D903

OLVG Oost, afd. Dermatologie, Amsterdam.

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

Clin Exp Dermatol 2017 Feb 28. Epub 2017 Feb 28.

Department of Dermatology, Centre Hospitalier Lyon-Sud, Hospices Civils de Lyon, Lyon, France.

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

Am J Dermatopathol 2017 Feb 2. Epub 2017 Feb 2.

*The Laboratoire Central d'Anatomie Pathologique, Hôpital L. Pasteur, University of Nice, Nice, France; and†Nail's Dermatology Consultations, Cannes, France.

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

J Cutan Aesthet Surg 2016 Oct-Dec;9(4):270-273

Sector of Dermatology, School of Medicine, University Hospital, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.

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

J Am Acad Dermatol 2017 Feb;76(2S1):S19-S21

Department of Dermatology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania. Electronic address:

Acta Chir Plast Fall 2016;58(1):43-45

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

Case Rep Dermatol Med 2016 13;2016:1853495. Epub 2016 Jul 13.

Department of Dermatology, Sainte Elisabeth Hospital, 5000 Namur, Belgium.

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

Skin Appendage Disord 2016 May 22;1(4):209-12. Epub 2016 Apr 22.

Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Fla., USA.

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

Skin Appendage Disord 2016 May 20;1(4):202-8. Epub 2016 Apr 20.

Nail Disorders Unit, Second Department of Dermatology, Attikon University Hospital, Athens, Greece.

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

Am J Dermatopathol 2017 Jan;39(1):40-44

*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

Cutis 2016 Apr;97(4):E15-8

Division of Dermatology, Loyola University Medical Center, Maywood, Illinois, USA.

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

Ann Dermatol 2016 Apr 31;28(2):237-41. Epub 2016 Mar 31.

Department of Dermatology, College of Medicine, The Catholic University of Korea, Seoul, Korea.

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

Am J Dermatopathol 2016 Sep;38(9):664-71

*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

Int J Dermatol 2016 Feb 6;55(2):e108-10. Epub 2015 Nov 6.

Department of Dermatology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.

Indian J Dermatol 2015 Sep-Oct;60(5):523

Department of Dermatology, Sri Manakula Vinayagar Medical college and hospital, Kalitheerthalkuppam, Madagadipet, Pondicherry, India.

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

Cutis 2015 Aug;96(2):121-4

Teaching and Research Office, Centro Dermatológico Federico Lleras Acosta, Ave 1, No 13A-61, Bogotá, Colombia.

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

Dermatology 2015 20;231(2):177-83. Epub 2015 Jun 20.

Department of Dermatology, Centre Hospitalier Lyon-Sud - Pierre Bénite, Hospices Civils de Lyon, Lyon, France.

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

Dermatol Surg 2015 Jun;41(6):753-5

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.

Br J Dermatol 2015 Nov 27;173(5):1305-7. Epub 2015 Aug 27.

Dermatology, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina, Brazil.

An Bras Dermatol 2015 Mar-Apr;90(2):265-7

Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil.

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

Am J Dermatopathol 2015 Jun;37(6):473-6

Department of Dermatology, Hospital of the University of Pennsylvania, Philadelphia, PA.

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

Dermatol Clin 2015 Apr 14;33(2):197-205. Epub 2015 Feb 14.

Department of Dermatology and Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, 1600 Northwest 10th Avenue, FL 33136, USA. Electronic address:

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

Indian J Dermatol 2015 Mar-Apr;60(2):212

Department of Dermatology, Venereology and Leprology, K.J. Somaiya Medical College, Mumbai, India.

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

J Cutan Pathol 2015 May 6;42(5):361-7. Epub 2015 Apr 6.

Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xian, China.

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

Skin Appendage Disord 2015 Mar 3;1(1):14-7. Epub 2015 Feb 3.

Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Fla., USA.

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

J Eur Acad Dermatol Venereol 2016 Mar 29;30(3):525-7. Epub 2014 Dec 29.

Dermatologic Surgery and Oncology Department, Hospital General de México "Dr. Eduardo Liceaga", Mexico City, Mexico.

Ann Dermatol Venereol 2014 Oct 16;141(10):634-5. Epub 2014 Sep 16.

Service de dermatologie, hôpital du Haut-Levêque, CHU de Bordeaux, avenue de Magellan, 33600 Pessac, France. Electronic address:

J Foot Ankle Surg 2015 Jul-Aug;54(4):723-5. Epub 2014 Jul 22.

Assistant Professor, Department of Dermatology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA.

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

J Cutan Pathol 2014 Oct 28;41(10):783-6. Epub 2014 Jul 28.

Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xian, China.

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

J Cutan Pathol 2014 Jul;41(7):555-60

Departments of Pathology, Hospital El Bierzo, Ponferrada, Spain; Departments of Dermatology, Hospital El Bierzo, Ponferrada, Spain.

Acta Derm Venereol 2014 Nov;94(6):747-8

Department of Dermatology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, 40025 PFP, Iowa City, IA 52242, USA.

Ann Dermatol Venereol 2014 Jan 11;141(1):79-82. Epub 2013 Oct 11.

Service de dermatologie, CHU Ibn Rochd, 1, rue des Hôpitaux, Casablanca, Maroc.

J Am Acad Dermatol 2014 Feb;70(2):395-7

Hershey and Philadelphia, Pennsylvania, and Bern, Switzerland.

Clin Exp Dermatol 2013 Dec;38(8):917-20

Department of Dermatology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.

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

Acta Dermatovenerol Croat 2013 ;21(3):198-201

Professor Emel Öztürk Durmaz, MD, Acıbadem Maslak Hospital, Büyükdere Caddesi 40, Maslak 34457, İstanbul, Turkey;

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

J Eur Acad Dermatol Venereol 2014 Nov 24;28(11):1560-2. Epub 2013 Sep 24.

Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, USA.

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

Clin Dermatol 2013 Sep-Oct;31(5):602-17

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

Am J Dermatopathol 2013 Oct;35(7):693-709; quiz 710-2

Dermatopathologist and Dermatologist, Laboratoire Central d'Anatomie Pathologique, Hôpital Pasteur, University of Nice, Nice, France.

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

Ann Dermatol 2013 Aug 13;25(3):394-5. Epub 2013 Aug 13.

Department of Dermatology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.

Am J Dermatopathol 2013 Aug;35(6):621-36

Dermatopathologist and Dermatologist, Laboratoire Central d'Anatomie Pathologique, Hôpital Pasteur, University of Nice, Nice, France.

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

J Cutan Pathol 2013 Jun 22;40(6):591-4. Epub 2013 Mar 22.

Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.

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

Am J Dermatopathol 2013 Aug;35(6):679-84

Laboratoire Central d'Anatomie Pathologique, Hôpital Pasteur, University of Nice, Nice, France. xst.perrin

We have recently described a new nail tumor known as onychocytic matricoma. Herein, we describe its malignant counterpart. Clinically, the tumor simulates onychomatricoma (OM). Read More

Dermatol Clin 2012 Oct 13;30(4):623-41, vi. Epub 2012 Aug 13.

Department of Pathology, Mount Sinai School of Medicine, One Gustave L Levy Place, New York, NY 10029, USA.

This article reviews the recent dermatopathology literature involving nonmelanocytic neoplasia, with a focus on important work done over the last 5 years. The discussion includes advances in the understanding of Merkel cell carcinoma pathogenesis and prognosis; changes in the seventh edition of the American Joint Committee of Cancer staging manual in reference to staging of squamous cell carcinoma and Merkel cell carcinoma; newly described or rare histopathologic patterns and entities including squamoid eccrine ductal carcinoma, rippled-pattern adnexal neoplasms, onychomatricoma, spindle cell predominant trichodiscoma/neurofollicular hamartoma, and myoepithelioma; and microsatellite instability in sebaceous neoplasms of Muir-Torre syndrome and other tumors. Read More

Indian J Dermatol Venereol Leprol 2012 May-Jun;78(3):382-3

Am J Dermatopathol 2012 Feb;34(1):54-9

Laboratoire Central d'Anatomie Pathologique, Hôpital Pasteur, University of Nice, France.

Among the tumors of the epidermal appendages, only rare tumors have been proved as differentiating in the direction of the nail. Beside onychomatricoma, we report a new matrical tumor of the nail: onychocytic matricoma (acanthoma of the nail matrix producing onychocytes). The main differential diagnosis of onychocytic matricoma is seborrheic keratosis. Read More

Foot Ankle Spec 2012 Feb 30;5(1):41-4. Epub 2011 Sep 30.

University of California-Los Angeles, CA, USA.

Onychomatricoma (OM) is a fibroepithelial tumor of nail matrix that occurs in the digits of both the hands and feet. This was first reported by Baran and Kint. They initially described 3 cases, all of which demonstrated a filamentous tumor of matrix tissue that resulted in a thickened funnel-shaped nail. Read More