Adult and Pediatric Nail Unit Melanoma: Epidemiology, Diagnosis, and Treatment

Transverse V-Y advancement composite tissue flap for repairing defects after longitudinal melanonychia excision-a retrospective cohort study

Longitudinal melanonychia (LM) is a common nail disorder that sometimes requires surgical excision to rule out malignancy. However, longitudinal complete removal of LM, as one type of method for some special patient, can leave a significant defect in the nail bed. We introduced and assessed the application of transverse V-Y advancement composite tissue flap, a novel surgical procedure designed to address these defects. From September 2017 to January 2024, a total of 17 patients with LM underwent complete excision of the affected nail bed. The tissue defects ranged from 3 to 8 mm in width. The wounds were repaired using the transverse V-Y advancement composite tissue flap, which included the nail, nail fold, and adjacent finger pulp skin. All patients were followed up to assess flap survival, nail regrowth, and functional outcomes, and the mean follow-up time was 14 months, with a range of 6-23 months. All 17 flaps survived without complications. Nail regrowth was satisfactory in 15 cases, with only 2 cases showing a slight longitudinal ridge. Sensory recovery was well in all patients. Recurrence of LM was observed in 1 case (5.9%) during the follow-up period. The transverse V-Y advancement composite tissue flap is a reliable and effective alternative for repairing defects after LM complete excision identified as the indicating lesion, particularly for defects ranging from 3 to 8 mm in width. This technique significantly improves both functional and cosmetic outcomes, with high patient satisfaction.

Advances in image-based diagnosis of nail disorders

This paper provides a comprehensive overview of image-based techniques, particularly focusing on their applications and advancements in the context of nail disorders. Nowadays, high-resolution digital cameras and dermoscopes enable dermatologists to capture detailed images of nail abnormalities, facilitating early diagnosis and meticulous tracking of disease progression. Onychoscopy is now a routine technique with well-known criteria for the diagnosis, but recent developments allow us to visualize certain diseases better. Imaging modalities like high-frequency ultrasound, magnetic resonance imaging, optical coherence tomography and confocal microscopy are being increasingly adopted for their superior diagnostic capabilities. These techniques are described in their technology, scanning protocols, normal findings, advantages and limitations. Moreover, the integration of technology in patient education has fostered a more informed patient population, capable of actively participating in their disease monitoring and treatment regimens. Proper training, validation, regulation and ethical considerations are, however, essential when integrating technology into healthcare practices. Imaging technologies that present the potential to add critical anatomical information to clinical diagnoses within reasonable costs and are available worldwide are the ones that will probably be used the most.

Clinical Characteristics of Nail Unit Melanoma in Türkiye: The Experience of Two Tertiary Dermatology Centers

Background

The literature on the clinical presentations of nail unit melanoma (NUM) in different countries is limited.

Aims

To assess the specific clinical characteristics of NUM in Türkiye.

Study Design

A retrospective cross sectional study.

Methods

Patients with NUM in two centers were retrospectively evaluated for their clinicopathological features, including the location, laterality, destruction of the nail plate, erosion or ulceration, presence of longitudinal melanonychia (LM), Hutchinson's sign (HS), and the absence of pigmentation and Breslow thickness. These variables were compared in terms of the main location of the NUMs (fingernail versus toenail).

Results

A total of 37 patients (54.1% female) of mean age 61.9 ± 14.8 years were enrolled. In most cases, NUMs were located in the fingernails (62.2%), with the most common location being the thumbnails (45.9%), followed by the big toenails (32.4%). Five cases had in situ melanoma presenting with LM. The mean Breslow thickness of invasive NUM lesions (n = 26) was 4.7 ± 4.1 mm (median: 3). Although all in situ NUMs were located on the hands, no statistically significant difference was noted in the Breslow thickness of invasive NUMs on the toenails and fingernails. NUMs were hypomelanotic/amelanotic in 10 (27%) patients. LM was clinically evident in 40.5% of the patients and was significantly more frequently observed on fingernails. The HS of the nail folds was noted in 40.5% of the patients, with the proximal (73.3%) and distal (73.3%) nail folds being most commonly involved. Total or partial destruction of the nail plate was recorded in 24.3% and 51.4% of the patients, respectively. Erosion and/or ulceration on the surface of the NUM was clinically present in most (75.7%) cases. Invasive NUMs associated with LM (n = 10) displayed partial destruction of the nail plate (n = 9), erosion and/or ulceration on the tumor surface (n = 7), and HS (n = 6).

Conclusion

The clinical characteristics of patients with NUM, such as more common localization on the hands, a high rate of preference for thumbnail and big toe, and the ratio of HS, were similar to the studies reported from diverse countries. Partial destruction of the nail plate is an important clinical feature of NUM. Furthermore, LM is more frequently observed in NUMs on the fingernails.

Evaluation and diagnosis of longitudinal melanonychia: A clinical review by a nail expert group

Longitudinal melanonychia (LM), a brown-black band on 1 or multiple nails, is commonly encountered in clinical practice. Benign LM may be due to exogenous (external, blood, bacterial, mycotic) or endogenous (melanin) pigment. Histopathologically, melanin-derived LM may result from overproduction of melanin by a normal number of melanocytes (melanocytic activation) due to physiologic, local, systemic, iatrogenic, syndromic, and drug-induced causes, or from benign (nail matrix nevus and lentigo) or malignant (nail unit melanoma [NUM]) melanocyte hyperplasia. A high index of suspicion is necessary to differentiate benign LM and NUM secondary to similarities in clinical presentation, especially in pediatric patients. Benign pediatric LM may exhibit clinical and onychoscopic features resembling adult NUM; thus, a conservative approach with close follow-up is recommended. Onychoscopy and histopathologic examination of nail clippings are useful initial diagnostic tools for LM, avoiding a biopsy or aiding in biopsy planning and patient triage. Nail matrix excisional biopsy is the gold standard for diagnosing/ruling out NUM. For suspicious LM, a nail matrix tangential excisional biopsy is recommended. A longitudinal excision is recommended for cases with a high-likelihood of invasive NUM, which provides information on tumor extension. Herein, we review the current literature to describe the evaluation and diagnosis of LM.

Melanoma in patients with skin of color

Cutaneous melanoma is far less common in skin of color patients than in non-Hispanic White individuals but carries a poorer prognosis. Melanomas in skin of color populations are more often identified on sun-protected locations such as acral surfaces, nail units, and mucous membranes, making them challenging to detect in early stages due to unfamiliar clinical and dermatoscopic features. Additionally, racial health care disparities compound the difficulty in diagnosis and ultimately contribute to poorer prognosis. We explore the epidemiology, clinical presentation, and health care disparities surrounding melanoma in skin of color individuals to increase awareness of the intricacies and nuances in identifying these malignancies.

New Insights in Paediatric Dermatopathology-2nd Edition

Paediatric dermatology is still an expanding subspeciality, which is well illustrated by the growing number of books and articles that have been published on this subject in recent years [...].

A rare and challenging case of amelanotic subungual melanoma from Syria

Subungual melanoma accounts for 1.9% of cutaneous melanomas. Amelanotic cases, comprising 15-25%, poses a significant diagnostic challenge because it can be misdiagnosed as other traumatic, inflammatory, or neoplastic conditions. This often leads to delayed diagnosis and subsequently, a poor prognosis. We present a case of an 83-year-old woman with a bleeding, painful and progressive lesion on the nail area of her right middle finger initially misdiagnosed as paronychia at a rural clinic four months ago. An incisional biopsy confirmed the diagnosis of amelanotic subungual melanoma. Amputation of the affected finger was performed successfully. Imaging studies showed no metastatic disease. This case underscores the importance of early recognition and management of subungual melanoma, particularly in remote rural areas, to optimize patient outcomes.

Brunelli (Dorsoulnar) Flap for the Reconstruction of Defect of the Thumb Nail Unit After Oncological Resections With Mohs Micrographic Surgery

Background

The Brunelli flap is an option in the reconstruction of the thumb after trauma or oncological resections. The arc of movement of the flap makes it possible to resolve defects in the proximal, palmar, dorsal, and lateral regions.

Methods

We present a case series of 11 patients in whom a Brunelli flap was performed for postoncological reconstruction, melanoma in situ, and invasive squamous cell carcinoma of the thumb nail unit associated with Mohs micrographic surgery. This combination has not been described before.

Results

The reconstruction was carried out using a Brunelli flap, incorporating certain variations to the original technique. Clinical follow-up was performed during a 1-year period. All flaps showed good viability. In 3 flaps, there was mild distal suffering that resolved with local healing. Three patients presented hypersensitivity in the distal part, which was managed with physical therapy. The functionality of the thumb was not altered in any case, and there were no complications in the donor site. No tumor recurrence was documented in any patient.

Conclusions

The use of the Brunelli flap to reconstruct the nail unit after an oncological resection with Mohs surgery is a good alternative. The advantages include a dorsal artery as a constant vessel and a homodigital flap that does not cause morbidity in the donor area, and with Mohs surgery, amputation is avoided. Disadvantages include lack of sensation of the flap. Some limitations of our study are the sample size and lack of long-term follow-up.

A Case of Rapid Transformation of a Nail Matrix Nevi to Melanoma After Messenger RNA COVID-19 Vaccine: A Cause or a Coincidence?

Subungual melanoma is a variant of acral lentiginous melanoma that arises from the nail matrix. Subungual melanomas present unique clinical challenges due to diagnostic difficulties and the lack of a standardized protocol for surveillance, also, there are no evidence-based studies that determine the ideal frequency and duration of clinical and dermoscopy follow-ups in patients with longitudinal melanonychia. This is highlighted by a case of longitudinal melanonychia in a 53-year-old patient who underwent malignant transformation to subungual melanoma after a biphasic growth. Another problem raised is how long to observe longitudinal melanonychia, with the conclusion that it should be observed for lifetime. Finally, this report also illustrates the possible role of the COVID-19 messenger RNA vaccine in cancer development and/or progression.

Pediatric Nail Disorders

Background

Pediatric nail disorders encompass a broad range of conditions. This article aimed to consolidate current knowledge on pediatric nail disorders to enhance diagnostic proficiency and clinical management among healthcare professionals.

Summary

Pediatric nail disorders present a diagnostic challenge due to their diverse nature. Non-syndromic congenital nail disorders encompass various anomalies such as anonychia/hyponychia, congenital malalignment of the great toenail, and racket thumbs, each with distinct clinical presentations and genetic associations. Syndromic congenital nail disorders, often part of complex syndromes, are characterized by unique features and associated abnormalities. Acquired nail diseases in children, like Beau's lines and onychomadesis, typically result from trauma or infection, while melanonychia, although rare in children, requires careful monitoring for potential malignant alterations, with consideration for biopsy in cases with concerning features.

Key Messages

(1) Pediatric nail disorders may pose diagnostic challenges and require a comprehensive understanding of nail anatomy and development. (2) Congenital nail disorders encompass isolated anomalies and syndromic associations, necessitating thorough evaluation for associated systemic conditions. (3) Acquired nail diseases may indicate underlying trauma or systemic illness and require careful assessment.(4) Melanonychia in children requires ongoing monitoring and evaluation, emphasizing the importance of consistent follow-up and histopathological examination when necessary.

Is Raman Spectroscopy of Fingernails a Promising Tool for Diagnosing Systemic and Dermatological Diseases in Adult and Pediatric Populations?

Background: Raman spectroscopy is a well-known tool used in criminology, molecular biology, and histology. It is also applied to diagnose bone mineral disorders by taking advantage of the similarity of the structure of keratin and bone collagen. Raman spectroscopy can also be used in dermatology and diabetology. The purpose of the present review is to critically evaluate the available research about the use of Raman spectroscopy in the mentioned areas of medicine. Methodology: PubMed was searched for peer-reviewed articles on the subject of use of Raman spectroscopy in bone mineral disorders, dermatology, and diabetes mellitus. Results: Nail keratin and bone collagen are related structural proteins that require disulfide bond for structural stability. Therefore, Raman spectroscopy of keratin may have potential as a diagnostic tool for screening bone quality and distinguishing patients at risk of fracture for reasons different from low bone mineral density (BMD) in the adult women population. Raman spectroscopy can also investigate the changes in keratin's structure in nails affected by onychomycosis and distinguish between healthy and onychomycosis nail samples. It could also reduce the need for nail biopsy by distinguishing between dermatophytic and non-dermatophytic agents of onychomycosis. Additionally, Raman spectroscopy could expedite the diagnostic process in psoriasis (by assessing the secondary structure of keratin) and in diabetes mellitus (by examining the protein glycation level). Conclusions: In adult populations, Raman spectroscopy is a promising and safe method for assessing the structure of fingernails. However, data are scarce in the pediatric population; therefore, more studies are required in children.

Melanoma-like features in pediatric longitudinal melanonychia: A systematic review and meta-analysis

BACKGROUND

Pediatric longitudinal melanonychia (LM) can exhibit atypical features that mimic red-flag signs for subungual melanoma in adults and lead to diagnostic uncertainty. Nail biopsy may be unnecessary if clinical inspection and dermoscopy suggest a benign nature.

METHODS

We searched PubMed and Embase from inception to February 2023 for studies of any design reporting either the number or proportion of clinical and dermoscopic features in at least five children (≤18 years) with LM. Non-English articles, reviews, and abstracts were excluded. We performed a systematic review and meta-analysis to collate all existing data.

RESULTS

A total of 1218 articles were screened and 24 studies with 1391 pediatric patients were included. Nevus was the most common diagnosis (86.3%). The most prevalent sites were fingernails (76.2%) and first digits (45.4%). Pooled proportions of common features were: dark-color bands (69.8%), multi-colored bands (47.6%), broad bandwidth (41.1%), pseudo-Hutchinson sign (41.0%), irregular patterns (38.1%), Hutchinson sign (23.7%), dots and globules (22.5%), nail dystrophy (18.2%), and triangular sign (10.9%). Outcomes included progression (widening or darkening, 29.9%), stability (23.3%), and spontaneous regression (narrowing or fading, 19.9%). Only eight cases of subungual melanoma in situ were reported, and no invasive melanomas were identified.

CONCLUSION

Although atypical characteristics are common in pediatric LM, the probability of malignant transformation is exceedingly low. Appropriate evaluation and management of pediatric LM includes careful clinical and dermoscopic inspection with attention to benign features followed by long-term interval follow-up.

PAK1 and Therapy Resistance in Melanoma

Malignant melanoma claims more lives than any other skin malignancy. While primary melanomas are usually cured via surgical excision, the metastatic form of the disease portents a poor prognosis. Decades of intense research has yielded an extensive armamentarium of anti-melanoma therapies, ranging from genotoxic chemo- and radiotherapies to targeted interventions in specific signaling pathways and immune functions. Unfortunately, even the most up-to-date embodiments of these therapies are not curative for the majority of metastatic melanoma patients, and the need to improve their efficacy is widely recognized. Here, we review the reports that implicate p21-regulated kinase 1 (PAK1) and PAK1-related pathways in the response of melanoma to various therapeutic modalities. Ample data suggest that PAK1 may decrease cell sensitivity to programmed cell death, provide additional stimulation to growth-promoting molecular pathways, and contribute to the creation of an immunosuppressive tumor microenvironment. Accordingly, there is mounting evidence that the concomitant inhibition of PAK1 enhances the potency of various anti-melanoma regimens. Overall, the available information suggests that a safe and effective inhibition of PAK1-dependent molecular processes would enhance the potency of the currently available anti-melanoma treatments, although considerable challenges in implementing such strategies still exist.