Nail tumors

Onychomatricomas: A 41-Case Series to Assess Surgical Outcome

BACKGROUND

Onychomatricoma (OM) is a rare benign tumor of the nail matrix. Treatment is surgical, but data are currently limited.

OBJECTIVE

To review all cases of OM operated in their department and to assess the link between the location on the nail plate, the thickness and width of the lesion, and the postoperative outcomes.

MATERIALS AND METHODS

Records of 62 patients were retrieved from their department's database over a 25-year period (1998-2023).

RESULTS

Of the 62 patients, 41 were eligible. In total, 58% of OM occupied a width of a quarter of the nail plate, 51% had a plate thinner than 3 mm, and 51% were laterally located. Of the 41 patients included, 29 had a tangential excision and 12 underwent lateral longitudinal excision. Among the tangential excision group, 71% had normal nail regrowth. Onychomatricoma thicker than 3 mm and involving the total nail plate width had a sequelae in 60% of cases.

CONCLUSION

Tangential excision of onychomatricomas allows a normal nail regrowth in 71% of cases. The risk of sequelae increases for tumors thicker than 3 mm and involving the total nail plate width. Medial or lateral location seems to have no influence.

High-frequency ultrasonography for subungual glomus tumor evaluation - imaging findings

OBJECTIVE

This article aimed to describe the common imaging features of subungual glomus tumors.

METHODS

The study involved data collected between January 2019 and December 2022. Twenty-three patients with a total of 31 glomus tumors underwent high-frequency ultrasound examinations with a 24-MHz probe. Two experienced radiologists independently evaluated the images, and only data from the more experienced radiologist were used for subsequent analyses.

RESULTS

The average size of the tumors was 4.6 mm, and most of them appeared homogeneously hypoechogenic (90.3%). Bone remodeling of the distal phalanx was observed in 87.1% of cases, with an average axial circumference loss of 0.8 mm, indicating the slow and expansive growth of glomus tumors. Intense vascularization was found in 54.8% of cases on Doppler images, and the stalk sign, reflecting the vascular origin of the tumor, was present in 64.5% of cases. The most common clinical feature was pain, reported in 84.6% of cases, with a mean pain scale score of 7.0, indicating a negative impact on patients' lives despite being benign tumors.

CONCLUSION

The study concludes that ultrasound evaluation is highly useful for diagnosing glomus tumors, especially when multiple findings, such as bone remodeling, hypervascularization, and the stalk sign, are present. This method allows for accurate diagnosis, observation of periungual structures, and proper surgical planning, ultimately reducing recurrence rates.

Examination of the nails: Main signs

Understanding the anatomy of the nail apparatus is a prerequisite for diagnosing and managing various nail disorders. The latter may be associated with systemic pathologies, or accompany infectious, inflammatory, tumoral, toxic or traumatic dermatoses. Before attempting to identify the cause, a rigorous clinical examination should be conducted to screen for elementary lesions that may affect general nail shape, nail surface, subungual attachments, periungual soft tissue or nail color. All of these guide differential diagnosis.

Nail dystrophy for the surgeon

Injuries to the fingertips are the most frequently occurring damage to the hand. The nail is an exceptional structure within the human body that offers both stability and protection, as well as the ability to perform fine and precise movements. Nail dystrophies are numerous, post-traumatic, post-infection or even degenerative. They raise many difficulties for the treating hand surgeon. Which anatomical structure is dystrophic? Is there any secondary fungal superinfection to be treated before surgery? Among the various techniques proposed, which one will help to improve my patient as a complete cure is rarer than partial failures. In this chapter we have chosen to describe the surgical techniques, their difficulties and drawbacks, that are available for the most frequent dystrophies that the hand surgeons may treat.

Surgery for benign nail tumor

The vast majority of tumors in the nail apparatus have a different clinical presentation and course from their equivalents on the skin. Some, such as onychomatricoma and onychopapilloma, are unique to the nail and others, such as superficial acral fibromyxoma, have a tropism for the nail apparatus. As a rule, benign lesions respect the general architecture of the nail apparatus, whereas malignant tumors are destructive. Treatment is always surgical and good knowledge of the anatomy and the procedures is mandatory in order not to induce postoperative nail dystrophy.

MRI of squamous cell carcinoma of the nail apparatus: report of 6 cases

Malignant tumors of the nail apparatus are rare and dominated by squamous cell carcinomas (SCC). Routinely, their pre-therapy imaging is limited to radiography. Our purpose is to determine the MRI characteristics in the locoregional assessment of SCC of the nail apparatus through a series of 6 consecutive cases explored by MRI and operated, carried out over a period of 12 years. IRB approval was obtained. Two in situ and 4 invasive squamous cell carcinomas were found, sex ratio was 0.5, and the age was 55 ± 10 years (mean ± SD). Most tumors showed specific signal behavior different from that of the epidermis and dermis with high signal on T2wi (5/6) and complete or partial enhancement (6/6). The mean thickness was 3.4 mm. The deep margin of the tumor with the dermis was always well defined for Bowen's disease (2/2) and blurred for invasive SCC. Localization involved the nail bed epithelium in all cases. Changes of the nail plate were detectable. Extension to lateral and posterior folds, hyponychium, cul-de-sac matrix, deep dermis, and bone was determined. MRI could be proposed as preoperative imaging of squamous cell carcinoma for locoregional assessment and guide biopsy.

Causes of longitudinal nail splitting: a retrospective 56-case series with clinical pathological correlation

BACKGROUND

Split nail (SN) is a rare type of nail fragility syndrome, characterized by a longitudinal fissure involving the entire thickness of the nail plate. Longitudinal nail splitting may be caused by direct injury to the nail plate or matrix insult. Few articles have been published on the topic, most were related to the traumatic aetiology. Some case reports mention tumours and inflammatory disorders as other causes.

OBJECTIVES AND METHODS

The aim of this retrospective study was to analyse the clinical and histopathological features of 56 SN collected at the nail consultation of the dermatology department at Saint Pierre University Hospital in Brussels, between 1997 and 2019.

RESULTS

Fifty-six patients were included (34 women and 22 men) with median age of 44.2 years. The fingernails were 3.2 times more frequently affected than toenails, especially the thumb. The most frequent aetiologies were tumours (45.6%), inflammatory diseases (26.3%) and traumas (19.3%). Congenital (5.3%) and systemic disorders (3.5%) were rarer causes. Histopathological slide review confirmed that alteration of the nail matrix integrity causes split nail, resulting either from matrix stretching by an underlying tumour or from impairment of the keratinization process by inflammatory diseases, melanocytic tumours and Bowen's disease.

CONCLUSIONS

This study is the largest case series of longitudinal nail splitting to date. It is the first to gather nail disorders causing SN with their clinical pathological correlation. The most common causes are traumatisms, tumours and inflammatory disorders. Congenital and systemic disorders are rarer. Tumours are responsible for half of the cases from which one third are malignant, mainly melanoma. When facing a monodactylic SN, benign as well as malignant tumours should be ruled out before concluding to traumatic aetiology.

Treatment Options and Outcomes for Squamous Cell Carcinoma of the Nail Unit: A Systematic Review

BACKGROUND

Nail squamous cell carcinoma (nSCC) is the most common nail unit malignancy. However, no studies to date have evaluated treatment options for nSCC based on recurrence data while controlling for invasion.

OBJECTIVE

To identify temporal trends in nSCC treatment modalities and compare treatment outcomes based on invasion.

METHODS AND MATERIALS

The authors performed a systematic review of articles published on PubMed, MEDLINE, and Scopus from inception to April 2020 reporting treatment of nSCC. The primary outcome was disease recurrence.

RESULTS

Reports of nSCC treatments have increased in the past decade. Mohs micrographic surgery (MMS) is the most common treatment reported overall. The lowest recurrence rates for in situ nSCC were seen with wide surgical excision (WSE) and MMS. For invasive disease, the recurrence rates were lowest with amputation, MMS, and WSE.

CONCLUSION

Complete surgical excision of nSCC with either WSE or MMS is associated with lower recurrence rates than limited excision and nonsurgical therapies, regardless of degree of invasion. The prognostic significance of in situ versus invasive disease remains unclear. Confirmation of complete excision may improve outcomes. Digital amputation is indicated for nSCC with bone invasion. Prospective studies and randomized controlled trials are needed to directly compare surgical modalities for nSCC.

Pigmented onychomatricoma: A clinical simulator that could not mislead ultrasound

INTRODUCTION

Onychomatricoma is a rare subungual tumor composed of stroma and nail matrix-like epithelium. Only seven cases of the pigmented variant have been reported in the literature.

CASE REPORT

We present a 62-year-old male patient with a 2-years history of a single fingernail thickening, deformation, and hyperpigmentation. He had been treated for onychomycosis, without improvement. Due to the increasing hyperpigmentation, and to rule out tumoral entities, including melanoma, a color Doppler ultrasound examination of the nail was requested, which showed a hypoechoic tumor of the nail matrix and bed, with hyperechogenic linear images inside, suggesting the diagnosis of onychomatricoma. Onychectomy and partial matricectomy were performed. Histological evaluation confirmed the diagnosis of onychomatricoma. Discusion and conclusion: Histological evaluation is the gold standard for the diagnosis of onychomatricoma. However, ultrasonography represents an easily accessible, non-invasive diagnostic tool for the initial evaluation of these tumors, especially in unsuspected atypical clinical presentations.

Nail Tumors

This article describes nail tumors and their clinical features, biologic behavior, and treatment. Tumors included are onychopapilloma, onychomatricoma, periungual fibromas/fibrokeratomas, glomus tumors, subungual exostosis, myxoid cysts, and squamous cell carcinoma.

Transillumination: A Diagnostic Tool to Assess Subungual Glomus Tumors

Diagnosis of subungual glomus tumors is mainly based on clinical symptoms, including paroxysmal pain, tenderness, and cold intolerance. Dermoscopy, ultrasonography, and MRI constitute further diagnostic tools, commonly performed to demarcate the tumor before surgery. Herein, we present 2 cases of subungual glomus tumors, which could be diagnosed after fingertip transillumination, highlighting that this technique can serve as an easy, noninvasive, and cost-effective adjuvant diagnostic tool, to facilitate the clinical diagnosis of subungual glomus tumors as well as their localization during preoperative assessment.

Painful nails: A practical approach to the diagnosis and management of painful nail conditions

Because several nail disorders share similar clinical features, their diagnosis and management can be challenging to clinicians. The physical examination may disclose localized abnormalities or point to an underlying systemic disease, requiring additional workup. Furthermore, cosmetic distress and nail-related symptoms (e.g., tingling, stinging, numbness, and pain) are common factors that influence the patient's search for medical assistance. Nail pain (i.e., onychalgia) can accompany both localized and systemic pathology. Onychalgia can be acute or chronic according to the time of evolution; patients may describe it as intermittent or constant, and as a throbbing, burning, sharp, or shooting sensation denoting the nature of the pain. It may be exacerbated by colder temperatures, touch, and increased activity (e.g., manipulating objects, walking). We present four main groups of conditions that might cause nail pain: nail tumors, nail deformities, inflammatory or infectious diseases, and external or traumatic agents. Our article includes an overview of the clinical features, as well as diagnosis and management pearls for each entity. Physicians (dermatologists and nondermatologists) should be aware that abnormalities of the ungual and subungual space are not exclusive of dermatological disorders but may also be present in noncutaneous contexts.

Pediatric Nail Disorders

Many pediatric nail findings are normal variants and are no cause for alarm. Others represent congenital abnormalities or genetic syndromes for which there is no cure. Still others are inflammatory or infectious entities that require treatment. Pediatric nail disorders are reviewed, along with management.

Onychalgia Causes and Mechanisms: The “GIFTED KID” and the “FOMITE”

This article gives an account of the commonest causes of nail pain. The acronyms GIFTED KID and FOMITE will help aid doctors in a busy clinical setting to remember the main causes of onychalgia, respectively, on the fingers and toes. It includes a brief overview of the clinical characteristics and focuses on the type of pain for each condition as well as the mechanisms that cause it.

Magnetic Resonance Imaging in the Diagnosis of Onychomatricoma: A Case Report

Onychomatricoma (OM) is a rare benign tumour of the nail matrix characterized by specific clinical and histologic features. The main clinical signs are thickening of the nail plate, xanthonychia, overcurvature of the nail plate, and multiple splinter haemorrhages. The diagnosis is based on clinical, radiological and histopathological findings. Histologically, the tumour is characterized by filiform epithelial projections. The objective of this study is to present the first reported Tunisian case of OM, focusing on the contribution of magnetic resonance imaging to the diagnosis of OM. A review on the subject is also presented.

Squamous Cell Carcinoma of the Nail Unit: A Clinical Histopathologic Study and a Proposal for Classification

BACKGROUND

There is no consensus on the classification, grading, and the treatment of nail squamous cell carcinoma (NSCC).

OBJECTIVE

The aim of the study was to propose a possible classification of NSCC.

MATERIALS AND METHODS

Nail squamous cell carcinoma referred from January 2006 till December 2014 was included. On the basis of the clinical presentation, patients with NSCC were divided in 2 groups. Group A tumors presented as nodular or ulcerated masses of the nail bed, whereas Group B tumors presented as hyperkeratotic bands. In these 2 groups, differences in proportions (sex, histopathologic grading, and treatment performed) were evaluated with the chi-square test.

RESULTS

Forty-one NSCCs were included. The groups of NSCC differed regarding: (1) the age of the patients, (2) histopathology, and (3) surgical approach.

CONCLUSION

Nail squamous cell carcinomas may originate from 2 different epithelia, presenting a diverse clinical behavior. The correct identification and diagnosis of each subgroup of NSCC could be helpful in standardizing management of this tumor. Future studies considering human papillomavirus subtyping and including a major number of tumors should be performed to confirm or reject the authors' hypothesis.

LIMITATIONS

This is a retrospective study, presenting the data and the experience of a single institute.

Squamous cell carcinoma of the nail unit

Squamous cell carcinoma (SCC) of the nail apparatus is a rare malignant tumor that usually originates underneath the nail plate and grows slowly with possible bone invasion. The etiology remains unknown, although a strong association with different conditions, such as high-risk human papillomavirus (HPVs), trauma, or radiation exposure has been demonstrated. Nail SCC is called "the great mimicker nail tumor" because different clinical presentations may coexist, resembling benign or malignant nail lesions. For this reason, there is often a significant delay between the onset of nail SCC and the diagnosis. Clinical manifestation includes onycholysis and erythema, while in the advanced stages nail ulceration can be observed. The association with pain, swelling, and inflammation usually indicates an invasive SCC with involvement of the underlying bone. Metastasis is rare but possible with involvement of lymph nodes. A multidisciplinary approach to assessment, management, and follow-up is advised. Using careful examination and modern diagnostic methods, including onychoscopy, biopsy, and histopathology, will help identify SCC and prevent the invasive progression. X-ray is important to investigate the bone invasion to determine the best surgical approach that will have satisfying cosmetic and functional outcomes. Nevertheless, local excision with sufficient surgical margins, best if using Mohs surgery, is usually sufficient and superior to amputation of the distal phalanx. This review aims to highlight the correct approach in suspected SCC of the nail unit.

Mohs micrographic surgery for nail unit tumours: an update and a critical review of the literature

Mohs micrographic surgery (MMS) is a good treatment option for epithelial neoplasms, especially when localized in areas where tissue conservation is crucial, such as the nail unit (NU). MMS is a method of radical excision offering high cure rates due to the margin control and functional preservation. Our aim is to provide a review on the use of MMS for the treatment of the most common nail tumours. We revised the current literature on the use of MMS to treat malignant neoplasms (Bowen's disease, squamous cell carcinoma, melanoma, basal cell carcinoma, keratoacanthoma, carcinoma cuniculatum) and benign neoplasms (onychomatricoma and glomus tumour). MMS represents a successful surgical option for nail tumours, firstly in terms of tissue conservation: the NU anatomy is complex and the preservation of the component structures is imperative for its functionality. Secondly, due to the surgical radicality, which is essential not only for the clearing of malignant tumours, but also for benign cases, in order to reduce recurrences. Although a conservative treatment of NU melanoma with MMS has been proposed, in our experience, the conservative approach with functional surgery is a good option for the treatment of non-invasive melanoma (in situ and Ia).

Subungual Solitary Angiokeratoma Simulating a Squamous Cell Carcinoma

Subungual angiokeratoma is extremely rare. Only 1 case is reported in the literature, presenting as a longitudinal pigmented band on a toenail. We report a case of a subungual angiokeratoma on a fingernail of a 43-year-old woman, clinically mimicking a squamous cell carcinoma. Medical imaging revealed a soft tissue tumor and erosion of the distal phalanx. Although extremely rare, solitary angiokeratomas may arise in the nail apparatus and should be added to the differential diagnosis of subungual warty tumors.

Nail neoplasms

Nail neoplasms include all tumors occurring in the nail or periungual apparatus tissue. While some nail tumors can be similar to tumors located on the skin, others are unique. Both benign and malignant lesions can affect the nail apparatus. In particular, early malignant tumors like melanoma and squamous cell carcinoma can present similarly to onychomycosis or benign melanonychia and frequently missed by clinicians. Therefore, physicians should be aware of nail structures and the characteristics of nail tumors. Our review covers the normal nail structure and the most common nail tumors from benign to malignant.

Subungual squamous cell carcinoma

Although subungual squamous cell carcinoma is rare, it is the most common primary malignant neoplasms in this location. The higher incidence occurs in the fingernails, but involvement of the toenails is also possible. Subungual squamous cell carcinoma often looks like other more common benign lesions, such as fungal infection, onychomycosis, or viral wart. These factors, together with a general lack of awareness of this disease among physicians, often result in delayed diagnosis. Therefore, it is underdiagnosed, with few reports in the literature. The authors present a case of a man with a diagnosis of subungual squamous cell carcinoma in the hallux, without bone involvement, which was submitted to the appropriate surgical treatment.

Clinico-pathologic, dermoscopic and ultrasound examination of a rare acral tumour involving the nail - case report and review of the literature

There is a large spectrum of tumors presenting as nodular lesions that may affect the subungual space. We report the case of a 62-year-old woman presenting with a rapidly growing nodular lesion under the nail of the first left toe. Non-invasive examinations using dermoscopy, ultrasonography and elastography were performed for the preoperative assessment of the lesion. The biopsy of the lesion revealed superficial acral fibromyxoma, a benign tumor with predisposition for acral sites. The patient underwent radical surgery with wide resection margins. This is the first case report of a superficial acral fibromyxoma affecting the subungual region characterized by dermoscopic, ultrasonographic and elastographic features. We also performed a short review of the literature.

Tips to diagnose uncommon nail disorders

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).