Use of Nail Dermoscopy in the Management of Melanonychia: Review

Seven Plus One Steps to Assess Pigmented Nail Bands (Melanonychia Striata Longitudinalis)

Melanonychia striata longitudinalis might involve one or more fingers and/or toes and might result from several different causes, including benign and malignant tumors, trauma, infections, and activation of melanocytes that might be reactive or related to the pigmentary trait, drugs and some rare syndromes. This broad differential diagnosis renders the clinical assessment of melanonychia striata particularly challenging. Nail matrix melanoma is relatively rare, occurs almost always in adults involves more frequently the first toe or thumb. The most common nail unit cancer, squamous cell carcinoma / Bowen disease (SCC) of the nail matrix is seldom pigmented. Histopathologic examination remains the gold standard for melanoma and SCC diagnosis, but excisional or partial biopsies from the nail matrix require training and is not routinely performed by the majority of clinicians. Furthermore, the histopathologic evaluation of melanocytic lesions of the nail matrix is particularly challenging, since early melanoma has only bland histopathologic alterations. Dermatoscopy of the nail plate and its free edge significantly improves the clinical diagnosis, since specific patterns have been associated to each one of the causes of melanonychia. Based on knowledge generated and published in the last decades, we propose herein a stepwise diagnostic approach for melanonychia striata longitudinalis: 1) Hemorrhage first 2) Age matters 3) Number of nails matters 4) Free edge matters 5) Brown or gray? 6) Size matters 7) Regular or irregular and, finally, "follow back".

Clinical and dermoscopic features of nail unit melanoma in an Australian nail clinic cohort

Nail unit melanoma carries diagnostic challenges conferring with its poor prognosis. This audit aims to characterise both clinical and dermoscopic features of nail unit malignant lesions and compare them with biopsied benign lesions. It focuses on informing future practice by aiding in the stratification and recognition of malignant diagnostic patterns in the Australian context.

Dermoscopic Evaluation of Longitudinal Melanonychia in Children: A Prospective Study

Background:

Longitudinal melanonychia (LM) is a worrisome sign in both children and adults. Nail apparatus melanoma (NAM) can be related to LM, but it is very rare in children. Dermoscopic signs of benign lesions in children can be similar to melanoma; therefore, it is important to review dermoscopy of LM in children to make the best decision in performing biopsy.

Aims:

Biopsy taking is very challenging in LM in children. Most lesions are benign in children. The aim of this study was to review dermoscopic signs of LM in children and compare them with adults.

Materials and Methods:

In this prospective study a total of 108 LM (35 children and 73 adults) were undergone dermoscopy of LM. Dermoscopic features were compared in children and adults; both for benign lesions proven by biopsy or follow up and melanomas diagnosed histopathologically.

Results:

Black background, black band color, band color diversity and pseudo-Hutchinson's sign were more frequent in children in comparison with benign adult melanonychia. Some children's dermoscopic features of LM such as broad band width, Band color diversity, Hutchinson's sign, gray band color, asymmetry of pattern, and regression were similar to melanoma, but we did not find any melanoma by biopsy and/or follow up among children. We also detected the newly described "zigzag" pattern in four children.

Conclusion:

Dermatologists should consider all dermoscopic features of a lesion, dermoscopic sign changes in follow-up, medical, and familial history of the patient in deciding to perform biopsy of LM in children.

Nail discoloration in pediatric skin of color patients

Nail pigmentation in children can cause significant anxiety in parents and clinicians. Different pigments of the nails, such as yellow, orange, and green, can all occur; however, this paper will focus on the dark pigments: brown, gray, and black pigmentation of the nails. Many causes of dark coloration of the nails exist; almost all causes in pediatric patients are benign and require no treatment. Melanoma is the one diagnosis that physicians do not want to miss. Fortunately, this is extremely rare in children.

Evolution of the Clinical, Dermoscopic and Pathologic Diagnosis of Melanoma

The conventional narrative states that the steadily rising incidence of melanoma among fair-skinned Caucasian populations during the last decades is caused by excessive UV-exposure. There is, however, no doubt that other factors had a significant impact on the rising incidence of melanoma. Pre-1980s the clinical diagnosis of melanoma was based on gross criteria such as ulceration or bleeding. Melanomas were often diagnosed in advanced stages when the prognosis was grim. In the mid-1980s education campaigns such as the propagation of the ABCD criteria, which addressed health care professionals and the public alike, shifted the focus towards early recognition. Dermatoscopy, which became increasingly popular in the mid-1990s, improved the accuracy for the diagnosis of melanoma in comparison to inspection with the unaided eye, especially for flat and small lesions lacking ABCD criteria. At the same time, pathologists began to lower their thresholds, particularly for the diagnosis of melanoma in situ. The melanoma epidemic that followed was mainly driven by an increase in the number of in situ or microinvasive melanomas. In a few decades, the landscape shifted from an undercalling to an overcalling of melanomas, a development that is now met with increased criticism. The gold standard of melanoma diagnosis is still conventional pathology, which is faced with low to moderate interobserver agreement. New insights in the molecular landscape of melanoma did not translate into techniques for the reliable diagnosis of gray zone lesions including small lesions. The aim of this review is to put our current view of melanoma diagnosis in historical context and to provide a narrative synthesis of its evolution. Based on this narrative I will provide suggestions on how to rebuild the trust in melanoma diagnosis accuracy and in the benefit of early recognition.

The value of dermoscopy of the nail plate free edge and hyponychium

The non-invasive examination of the nail unit using a dermoscope is known as onychoscopy. This technique has become increasingly appreciated to facilitate the clinical diagnosis of nail disorders, opening up a valuable second front with a potential to avoid invasive diagnostic procedures. During a nail consultation, the nail unit should always be examined with the aid of a dermatoscope in all its components. The aim of this paper is to provide practical information about onychoscopy of the nail plate free edge and hyponychium, two components of the nail unit difficult to evaluate at naked eye and often forgotten, but of paramount importance.

A cross-sectional study on clinico-dermoscopic features of periorbital melanosis in a tertiary care hospital

INTRODUCTION

Periorbital melanosis (POM) is an esthetic facial concern on increasing trend and has a severe emotional impact on patients. We aimed to study the clinical and dermoscopic patterns of periorbital melanosis to aid in the classification and strategize therapy.

METHODS

A cross-sectional, observational study was conducted on one hundred patients with POM in a tertiary care center in India from January 2020-March 2020. Dermoscopic assessment of POM was done using video dermatoscope- FotoFinder Medicam 1000s (magnification up to 140x).

RESULTS

The mean age of participants was 32.8 ± 9 years. It was more prevalent among females (78%). The constitutional type (43%) of POM was the most common followed by shadow-effect type (32%). The various dermoscopic pigmentary patterns seen were scattered pigmented dots (56%), exaggerated pigment network (31%), globules (30%), and blotches (27%). Dilated veins and telangiectasia were seen in 50% and 32% of subjects, respectively. Exaggerated skin markings were seen in 43% of participants. Scattered pigmented dots were most commonly seen in constitutional, vascular, and shadow types but were significantly associated with vascular type. Exaggerated pigment network was the most frequent pigmentary pattern in post-inflammatory type of POM. Globules were significantly associated with constitutional as well as shadow type of POM and blotches with shadow type of POM.

CONCLUSIONS

Periorbital melanosis presents as multifactorial entity with constitutional type being the most common. The dermoscopic patterns of POM may provide a clue to the underlying etiology, thereby helping to plan appropriate treatment.

Diagnosis of Melanonychia

Melanonychia has many causes and can involve one or several fingernails or toenails, and may occur at any age. Dermoscopy is used routinely in the evaluation of a pigmented nail. If pigmentation is caused by melanin produced by nail matrix, identify whether the pigmentation is caused by an activation or proliferation of nail melanocytes. When melanocytic proliferation is suspected, biopsy with histopathologic examination is the gold standard for diagnosis and is recommended when a longitudinal melanonychia occurs in an adult and is localized in a single digit, in the absence of local or systemic causes that may explain its onset.

Dermoscopy of the Nail Unit

Nail dermoscopy (onychoscopy) is being used for a more accurate diagnosis of all nail disorders and has become a routine diagnostic instrument. In daily practice, nail signs can be magnified, and dermoscopy may confirm the clinical diagnosis and guides in management of nail diseases and treatments, permitting a better visualization of symptoms. Onychoscopy is used by the experts in almost all nail diseases. It can be performed dry or with ultrasound gel in order to make the stratum corneum translucent, depending on which part of the nail unit has to be evaluated.

Dermatophytic melanonychia: A case series of an increasing disease

BACKGROUND

Melanonychia refers to brown-black colour pigmentation due to melanin or not-melanin deposition in the nail plate. Onychoscopy allows to distinguish if the pigmentation is due by melanin or not. The main causes of non-melanic pigmentation are subungual haematoma and pigmented onychomycosis. Fungal melanonychia (FM) is rare and may present as diffuse or longitudinal pigmentation. Differential diagnosis includes melanic activation, such as ethnic-type nail pigmentation or frictional melanonychia, but also versus melanic proliferation, such as nevus or nail melanoma. Fungal melanonychia can be due to a colonisation by fungi with black variant or by melanin activation due to inflammation of fungal invasion.

OBJECTIVES

The aim of paper is to increase clinical and dermoscopic knowledge of this increasingly frequent disease.

METHODS

In this retrospective observational study, twenty patients with dermatophytic melanonychia were collected, with available clinical and dermoscopic pictures. The diagnosis of dermatophytic melanonychia was made based on clinical manifestation and mycological examination. KOH smear was performed in all cases. For each patient, clinical data included: age, gender, type of melanonychia and involved fingers.

RESULTS

This study aimed to show increased incidence of dermatophytic melanonychia and its correct management. In addition, we reviewed our collected cases and described the clinical and dermoscopic features of dermatophytic melanonychia.

CONCLUSIONS

The results of this study showed that physicians should keep in mind the diagnosis of this increasing disease, and that it cannot be performed relying only on clinical grounds. We would like to highlight the importance of tools as KOH examination, culture and dermoscopy.

Melanonychia - Clues for a Correct Diagnosis

Melanonychia represents a brown to black discoloration of the nail plate that may be induced by benign or malignant causes. Two main mechanisms are involved in the appearance of melanonychias, i.e., melanocytic activation and melanocytic hyperplasia. The distinction between the two can be made based on the medical history of the patient, the clinical picture, dermoscopy, and histopathological examination and is essential for the adequate management of the patient. We review the main causes of melanonychia, with emphasis on the clues to the diagnosis of subungual melanoma.