Assessment of Patient Knowledge of Longitudinal Melanonychia: A Survey Study of Patients in Outpatient Clinics

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

Nail unit melanoma (NUM) is an uncommon form of melanoma and is often diagnosed at later stages. Approximately two-thirds of NUMs are present clinically as longitudinal melanonychia, but longitudinal melanonychia has a broad differential diagnosis. Clinical examination and dermoscopy are valuable for identifying nail findings concerning malignancy, but a biopsy with histopathology is necessary to confirm a diagnosis of NUM. Surgical treatment options for NUM include en bloc excision, digit amputation, and Mohs micrographic surgery. Newer treatments for advanced NUM include targeted and immune systemic therapies. NUM in pediatric patients is extremely rare and diagnosis is challenging since both qualitative and quantitative parameters have only been studied in adults. There is currently no consensus on management in children; for less concerning melanonychia, some physicians recommend close follow-up. However, some dermatologists argue that the "wait and see" approach can cause delayed diagnosis. This article serves to enhance the familiarity of NUM by highlighting its etiology, clinical presentations, diagnosis, and treatment options in both adults and children.

Clinical and dermoscopic findings of benign longitudinal melanonychia due to melanocytic activation differ by skin type and predict likelihood of nail matrix biopsy

BACKGROUND

Longitudinal melanonychia (LM) is a common dermatologic finding in clinical practice with a broad differential diagnosis. Melanocytic activation is the most common LM etiology.

OBJECTIVE

To investigate clinical and dermoscopic differences of benign LM based on Fitzpatrick skin type and in biopsied vs. non-biopsied patients.

METHODS

A 10-year retrospective cohort of 248 benign LM cases at Weill Cornell Dermatology was identified and analyzed.

RESULTS

Darker-skinned vs. lighter-skinned patients had higher band width percentage (p=0.0125), lower band brightness (p<0.001), more band changes (p=0.0071), and received more biopsies (p=0.032). Biopsied (n=47) vs. non-biopsied patients (n=201) had less multidigit band involvement (p=0.0008), higher band width percentage (p=0.0213), lower band brightness (p=0.0003), and more band changes (p<0.0001). Darker skin types more often had brown vs. grey coloration on dermoscopy (p=0.0232). Mean band width percentage for all biopsied patients was 30.81% (range: 5.80%-100%).

LIMITATIONS

Single-center retrospective design. Subungual melanoma and other benign LM etiologies were not analyzed. Only 18.95% of patients received a biopsy.

CONCLUSION

Darker vs. lighter skin types more often present with darker and wider bands, brown vs. grey coloration on dermoscopy, and receive more biopsies. Multi-institutional studies on LM are needed to determine nail matrix biopsy criteria in different skin types.

Assessment of internet sources on subungual melanoma

In this study, we sought to objectively determine the accuracy and comprehensibility of online material with regard to subungual melanoma, a nail disease that is rare within the general population, yet has high incidence in certain patient groups, and carries a poorer prognosis than other forms of cutaneous melanoma. Because improved prognosis relies on early diagnosis, the dissemination of accurate, understandable information is an important factor in patient education and health. Using a pro forma designed to score website reliability, the accountability, quality, readability, display, support features, and transparency of the most commonly listed search engine hits related to subungual melanoma were analyzed. A total of 27 websites were assessed, with a mean overall score of 16.1 out of a maximum of 40 (range: 7-25). Accountability (mean: 3.4/10, range: 0-9) and quality (mean: 4/10, range: 0-9) varied among websites, while readability was poor overall, with only 22% of websites meeting the accepted seventh grade reading level for online health material. In addition, commonly visited websites for health information, including Wikipedia.org and Medscape.com, scored low in readability. Notably, the American Academy of Dermatology website was not listed under any search engine results for subungual melanoma. Our study demonstrates the variability in online materials with regard to subungual melanoma, stressing the importance of scrutinizing internet resources for accuracy and readability when presenting health material.

Retrospective analysis of nail biopsies performed using the Medicare Provider Utilization and Payment Database 2012 to 2017

Subungual melanoma (SUM) is subset of acral melanoma that develops within the nail unit and is associated with a poor prognosis. Nail biopsy is the only way to definitively diagnosis SUM. Our objectives were to analyze the Medicare database for nail biopsy utilization and to compare the annual nail biopsy rate with the estimated incidence of SUM in the United States. A retrospective study on nail biopsy data was performed using the Medicare Provider Utilization and Payment Database 2012 to 2017. The number of nail biopsies performed per 100 000 people was compared to SUM incidence per 100 000 people. Podiatrists, dermatologists, other physicians, and NP/PAs respectively performed 12.12, 0.42, 0.08, 0.07 nail biopsies per 100 000 people annually. Dermatologists performed adequate nail biopsies to cover the minimum (0.7%), but not the maximum (3.5%) estimated incidence of SUM. Only 0.28% and 1.01% of general dermatologists and Mohs surgeons, respectively, performed nail biopsies in 19/50 (38.00%) states and 69/929 (7.42%) zip codes. Limitations of our study were that nail biopsies on patients less than 65 years, and those with no or commercial health insurance were not analyzed. In sum, very few dermatologists performed nail biopsies in the Medicare database. Increased efforts are needed to educate dermatologists on nail surgery.

Dermoscopic features of neoplasms in skin of color: A review

BACKGROUND

Dermoscopy is undoubtedly a useful tool to improve diagnostic accuracy and minimize the number of unnecessary biopsies. However, much of the literature on dermoscopy focuses on findings in lighter-skin phototypes, leaving potential gaps of knowledge regarding its use in skin of color (SoC). As the clinical applications of dermoscopy continue to increase, understanding dermoscopic patterns in SoC is imperative.

OBJECTIVE

This review discusses the literature on dermoscopic findings of neoplasms in SoC, highlighting unique and characteristic dermoscopic features.

METHODS

A literature review was performed using the PubMed database. Case reports, case series, case-control studies, and systematic reviews were included.

RESULTS

A total of 8326 studies were identified based on the selected search terms, and 41 were included in this review based on relevance.

CONCLUSION

There are specific dermoscopic characteristics in SoC for benign nevi, acral lentiginous melanoma, ethnic melanonychia, and dermatofibroma; however, there is a lack of published data about specific features of cutaneous melanoma, subungual melanoma, pigmented basal cell carcinoma, and pigmented squamous cell carcinoma in SoC. Because pigmented basal cell carcinoma, pigmented squamous cell carcinoma, ethnic melanonychia, and acral lentiginous melanoma are diagnosed at later stages in this population, it is important to understand their dermoscopic features. Further descriptive studies are needed to better characterize unique dermoscopic features in neoplasms in SoC.