"Lentiginous melanoma": full-fledged melanoma or melanoma precursor?

Clinicopathologically Defined Naevus Subtypes and Melanoma Risk

Early detection of melanoma is a major determinant in disease outcome and drives the number of (over)excised naevi in clinical practice. This study aimed to evaluate demographic features and melanoma risk of clinically suspicious, mainly flat naevus subtypes. Based on the methodology of ex vivo dermoscopy and derm dotting, the 12 most prevalent naevus subtypes were identified in a collection of over 7000 naevi excised for medical reason. Dermoscopical, histopathological and clinical features of these subtypes were described. In addition, the association with melanoma history, histopathological atypia and melanoma occurrence within naevi was compared. Nearly half of the naevi removed for medical reasons were of the hypermelanotic subtype with no or mild histopathological atypia and low melanoma association, suggesting overtreatment in daily practice. Contrarily, the subtypes atypical lentiginous naevus and orange pulverocytic flat naevus were associated with higher proportions of (severe) atypia and melanoma (history). We believe these subtypes may reflect different tumoural and/or (germline) genetic entities with different melanoma risk. The data from this study may direct further prospective research on specific naevus subtypes in order to obtain better insights in associated clinical/genetic factors and melanoma risk.

A Scoping Review and Population Study Regarding Prevalence and Histopathology of Juvenile Vulvar Melanocytic Lesions. A Recommendation

Cases of vulvar melanocytic lesions in juveniles are rarely reported. We analyze the evidence regarding vulvar melanocytic lesions in juveniles with or without vulvar lichen sclerosus to help decision making by clinicians and pathologists. A scoping review on vulvar melanocytic lesions with or without vulvar lichen sclerosus, including malignant vulvar melanomas, in females up to age 18 years was performed. In addition, the histopathology records of the cohort of all such lesions in The Netherlands from 1991 through 2020 were investigated, and a structured analysis of tissue samples of the subset of cases with lichen sclerosus was performed. The literature study performed confirms that vulvar melanomas in juveniles are extremely rare and that published case reports are often disputed. In The Netherlands, there are no cases of malignant vulvar melanomas up to age 18 years recorded from 1991 through 2020. Atypical histopathological features are often found in biopsies of vulvar nevi in juveniles, especially with concomitant lichen sclerosus, confirming earlier case studies in the literature. We conclude that even with atypical findings, vulvar melanocytic lesions in juveniles have a benign course. To avoid unnecessary and possibly mutilating procedures, we advise referral to an expert center and adaption of existing guidelines for vulvar melanocytic lesions in juveniles.

Interpretation of the Complex Melanoma Pathology Report

An ambiguous pathologic report can present a clinical dilemma to the treating surgeon. We describe lesions ranging from the potentially benign to the likely malignant. Correctly identifying features associated with higher-risk lesions has proven challenging given the overall good prognosis and low rate of events. An appropriate treatment plan generally requires discussion between the surgeon and an experienced dermatopathologist. When clinically indicated, additional testing may be used to further support or refute a diagnosis of melanoma. The indications for these techniques, the data to support their use, and the strengths and weakness of each are reviewed.

Atypical Melanocytic Proliferations: A Review of the Literature

BACKGROUND

Ambiguous histopathologic diagnoses represent a challenge for clinicians because of a lack of definitive diagnosis and related uncertainty about management.

OBJECTIVE

To review the literature on atypical melanocytic proliferations and detail synonymous terms, epidemiology, diagnostic work-up, histopathology, treatment, and prognosis.

METHODS

Databases from PubMed and Web of Science were searched for articles related to atypical melanocytic proliferations.

RESULTS

Intraepidermal melanocytic proliferations with features worrisome for possible melanoma in situ (MIS) are generally excised as for MIS. Reported rates of upstaging of such cases to invasive melanoma on review of the excision are very low. Because invasion, lymph node spread, and metastasis can occur in atypical melanocytic lesions with a thick intradermal component, these are often treated as for malignant melanoma.

CONCLUSION

Because the diagnosis dictates treatment, it is incumbent to establish a diagnosis as definitive as possible, obtaining second or third opinions and using ancillary studies when appropriate. When the diagnosis remains uncertain, it is difficult to provide guidelines for treatment. Clinical care decisions for patients with an uncertain diagnosis are best done on a case-by-case basis weighing probabilities of adverse outcomes against potential benefits and risks from various treatment options.

Improving diagnostic sensitivity of combined dermoscopy and reflectance confocal microscopy imaging through double reader concordance evaluation in telemedicine settings: A retrospective study of 1000 equivocal cases

BACKGROUND

Reflectance confocal microscopy (RCM) is an imaging device that permits non-invasive visualization of cellular morphology and has been shown to improve diagnostic accuracy of dermoscopically equivocal cutaneous lesions. The application of double reader concordance evaluation of dermoscopy-RCM image sets in retrospective settings and its potential application to telemedicine evaluation has not been tested in a large study population.

OBJECTIVE

To improve diagnostic sensitivity of RCM image diagnosis using a double reader concordance evaluation approach; to reduce mismanagement of equivocal cutaneous lesions in retrospective consultation and telemedicine settings.

METHODS

1000 combined dermoscopy-RCM image sets were evaluated in blind by 10 readers with advanced training and internship in dermoscopy and RCM evaluation. We compared sensitivity and specificity of single reader evaluation versus double reader concordance evaluation as well as the effect of diagnostic confidence on lesion management in a retrospective setting.

RESULTS

Single reader evaluation resulted in an overall sensitivity of 95.2% and specificity of 76.3%, with misdiagnosis of 8 melanomas, 4 basal cell carcinomas and 2 squamous cell carcinomas. Combined double reader evaluation resulted in an overall sensitivity of 98.3% and specificity of 65.5%, with misdiagnosis of 1 in-situ melanoma and 2 basal cell carcinomas.

CONCLUSION

Evaluation of dermoscopy-RCM image sets of cutaneous lesions by single reader evaluation in retrospective settings is limited by sensitivity levels that may result in potential mismanagement of malignant lesions. Double reader blind concordance evaluation may improve the sensitivity of diagnosis and management safety. The use of a second check can be implemented in telemedicine settings where expert consultation and second opinions may be required.