Digital dermoscopic changes during follow-up of de-novo and nevus-associated melanoma: a cohort study

Multiple Primary Melanoma: A Five-Year Prospective Single-Center Follow-Up Study of Two MC1R R/R Genotype Carriers

BACKGROUND

Multiple primary melanoma (MPM) is a diagnostic challenge even with ancillary imaging technologies available to dermatologists. In selected patients' phenotypes, the use of imaging approaches can help better understand lesion characteristics, and aid in early diagnosis and management.

METHODS

Under a 5-year prospective single-center follow-up, 58 s primary melanomas (SPMs) were diagnosed in two first-degree relatives, with fair skin color, red hair, green eyes, and personal history of one previous melanoma each. Patients' behavior and descriptive demographic data were collected from medical records. The information on the first two primary melanomas (PMs) were retrieved from pathology reports. The characteristics of 60 melanomas were collected from medical records, video dermoscopy software, and pathology reports. Reflectance confocal microscopy (RCM) was performed prior to excision of 22 randomly selected melanomas.

RESULTS

From February 2018 to May 2023, two patients underwent a pooled total of 214 excisional biopsies of suspect lesions, resulting in a combined benign versus malignant treatment ratio (NNT) of 2.0:1.0. The number of moles excised for each melanoma diagnosed (NNE) was 1.7:1.0 and 6.9:1.0 for the female and male patient respectively. The in-situ melanoma/invasive melanoma ratio (IIR) demonstrated a higher proportion of in-situ melanomas for both patients. From June 2018 to May 2023, a total of 58 SPMs were detected by the combination of total body skin exam (TBSE), total body skin photography (TBSP), digital dermoscopy (DD), and sequential digital dermoscopy imaging (SDDI) via comparative approach. The younger patient had her PM one month prior to the second and third cutaneous melanomas (CMs), characterizing a case of synchronous primary CM. The male older relative had a total of 7 nonsynchronous melanomas.

CONCLUSIONS

This CM cohort is composed of 83.3% in-situ melanoma and 16.7% invasive melanoma. Both patients had a higher percentage of SPM with clinical nevus-like morphology (84.5%), global dermoscopic pattern of asymmetric multiple component (60.3%) and located on the lower limbs (46.6%). When RCM was performed prior to excision, 81% of SPM had features suggestive of malignancy. As well, invasive melanomas were more frequent in the lower limbs (40%). In the multivariate model, for the two high-risk patients studied, the chance of a not associated with nevus ("de novo") invasive SPM diagnosis is 25 times greater than the chance of a diagnosis of a nevus-associated invasive SPM.

Dermoscopic features of nevoid melanoma: a retrospective study

BACKGROUND

Nevoid melanoma (NeM) is a rare variant of melanoma resembling melanocytic nevus. The aim of the study was to systematically review the dermoscopic features of NeM.

METHODS

A hospital-based retrospective study was conducted. Dermoscopic features of NeMs diagnosed through excisional biopsy between January 2015 1, and March 1, 2021, were compared to superficial spreading melanomas (SSMs) matched by Breslow's thickness. Then, a literature search was performed. Electronic searches on PubMed database via Medline were conducted to retrieve any manuscript reporting detailed dermoscopic features of histopathologically confirmed NeM.

RESULTS

A total of 60 malignant melanomas (MM) comprising 20 NeM and 40 SSM were collected. Twelve out of 20 (60%) NeM showed a nevus-like appearance, including reticular and globular patterns, and in 35% of these cases it was detected because of dermoscopic changes. Then, a total of seven original manuscripts were retrieved from the literature review, comprising 56 cases overall. NeM showed nevus-like pattern in 53% of the cases, multicomponent pattern in 21% and amelanotic in 9%. Enlargement, irregularly distributed dots/globules, irregular pigmentation, and atypical vascular pattern were found in NeM with nevus-like appearance. NeM with multicomponent pattern were characterized by irregular pigmentation, blue-white veil, irregular dots and atypical vascular pattern. Amelanotic NeM is rare and show atypical vascular pattern and milia-like cysts.

CONCLUSIONS

Dermoscopy of NeM is challenging as it frequently shows a nevus-like pattern, but clues and detection of dermoscopic changes may help to identify it.

A review of nevus-associated melanoma: What is the evidence?

Cutaneous melanoma may have an adjacent nevus remnant on histological examination in 30% of cases (nevus-associated melanoma, NAM), while it may appear de novo, without a precursor lesion, in the remaining 70% of cases. Nevus-associated melanoma and the concept of acquired melanocytic nevi serving as precursors of melanoma, has long been considered as a controversial topic. This controversy is, in part, due to their overall low rate of transformation to melanoma and scarce data on the natural history of progression. Another matter of debate regarded the possibility that the reported differences of NAM versus de novo melanoma, were due to an underestimation of NAM in thicker lesions due to obliteration of the nevus component by the tumour. During the last few years, several evidence has accumulated in order to address these controversies. In this review, we present a comprehensive synthesis of the epidemiological, clinical, dermoscopic and genetic findings in NAM, including thin NAM, compared to de novo melanoma. Answering the questions on nevus-associated melanoma may provide further insight on the classification of these tumours and disentangle their biology and route of development from that of de novo melanoma.

Are we born and do we die without nevi? A cross-sectional study

BACKGROUND

It is well known that the number of nevi varies with age. However, there are a few data in the literature concerning total nevus count at different ages. The aim of this study was to assess and compare the total nevus count among different age groups.

METHODS

The total nevus count was assessed in consecutive patients belonging to nine age groups. Median nevus count was calculated and compared for each age group. Multivariate logistic regression analysis was used to define the influence of sex and phototype on the association between nevus count and age.

RESULTS

We enrolled 900 patients (461, 51.2% females), with a median age of 46 years and a total of 18,136 nevi. Significant differences were found in the median total nevus count among all age groups (P < 0.001), with a significant increase in the first two decades and a significant decrease after the age of 50 years. A similar trend was also observed in subgroups. The differences observed in the total body nevus count among age groups were independent of sex and phototype.

CONCLUSIONS

We demonstrate that the total nevus count significantly increases during childhood and gradually decreases in the elderly.

Dynamic dermoscopic and reflectance confocal microscopic changes of melanocytic lesions excised during follow up

BACKGROUND

Digital dermoscopy follow up (DDF) is useful in improving the recognition of melanoma, catching early changes over time, although benign nevi can also show changes. Reflectance confocal microscopy (RCM) improves accuracy in diagnosing melanoma and decreases the number of unnecessary resections.

OBJECTIVE

To evaluate dynamic dermoscopic and RCM changes during follow up of equivocal melanocytic lesions and assess the impact of adjunctive RCM to DDF for melanoma diagnosis.

METHODS

A retrospective, multicenter study of extrafacial atypical melanocytic lesions excised during follow up was performed. Morphologic changes were evaluated, comparing dermoscopy and RCM baseline and follow-up images.

RESULTS

One hundred thirty-seven atypical melanocytic lesions were studied, including 14 melanomas and 123 benign nevi. Significantly greater changes in DDF of atypical network, regression, atypical streaks, and asymmetrical growth as well as in dynamic RCM of atypical cells and dermal-epidermal junction disarray were noted in melanomas. With adjunctive dynamic RCM and major changes at DDF, sensitivity reached 100%, with 40.6% specificity.

LIMITATIONS

Selected series of difficult to recognize lesions, with both DDF and dynamic RCM images.

CONCLUSION

Adjunctive dynamic RCM improves early melanoma recognition sensitivity.

The differences in clinical and dermoscopic features between in situ and invasive nevus-associated melanomas and de novo melanomas

BACKGROUND

Nevus-associated melanomas (NAM) account for 30% of all melanomas and are associated with younger age and with thinner Breslow thickness. Previous studies of NAM dermoscopy found conflicting results.

OBJECTIVE

To compare the clinical and dermoscopic features of NAM and de novo melanomas (DNM), stratified by melanoma thickness, in a relatively large cohort of patients.

METHODS

A cross-sectional study of all melanomas biopsied between 2004 and 2019 at a large cancer centre. Lesions were categorized as in situ and invasive NAM or DNM. Dermoscopic images were reviewed and annotated. Associations between melanoma subtype and dermoscopic features were analysed via logistic regression modelling. Bivariate analyses were conducted using non-parametric bootstrap and chi-squared methods.

RESULTS

The study included 160 NAM (86 in situ and 74 invasive) and 218 DNM (109 in situ and 109 invasive). NAM were associated with younger age, greater likelihood of being present on the torso, and thinner Breslow thickness. NAM were 2.5 times more likely to show a negative pigment network than DNM. In situ NAM were 2.1 and two times more likely to display dermoscopic area without definable structures and tan structureless areas than DNM, respectively. In situ melanomas were more likely to present a pigment network, and invasive melanomas more commonly presented scar-like depigmentation and shiny white structures. Streaks, blotches and shiny white structures were associated with deeper Breslow depth.

CONCLUSIONS

Even though the nevus component of NAM could not be identified dermoscopically in the current series, negative pigment network, tan structureless areas and areas without definable structures are dermoscopic clues for NAM.