High regional mortality due to malignant melanoma in Eastern Finland may be explained by the increase in aggressive melanoma types

Background A regional skin cancer prevention program in Eastern Finland revealed a relatively high age-standardized mortality due to malignant melanoma during 2013–2017. An explanation for this is needed. Purpose To analyse the 543 melanoma samples in 524 subjects collected during 2000–2013 at Kuopio University Hospital and reposited in the Biobank of Eastern Finland. A focus was directed to factors related to metastasis. Methods The samples were analysed anonymously by examining the histopathological report, referral text and the list of diagnoses. A possible state of immunosuppression was evaluated. Results The mean age at the diagnosis of malignant melanoma (MM), lentigo maligna (LM) and melanoma in situ was relatively high, i.e., 66.2, 72.1 and 63.3, respectively. Especially the MM type increased markedly during 2000–2013. In further analyses of a representative cohort of 337 samples, the proportion of nodular melanoma and LM/LMM melanoma was relatively high, 35.6 and 22.0%, respectively, but that from superficial spreading melanoma relatively low (33.8%). Metastasis correlated with immunosuppression, male gender, Clark level, Breslow thickness, ulceration, mitosis count, invasion into vessels and/or perineural area, microsatellites, melanoma subtype, body site, recidivism, and the absence of dysplastic nevus cells. Conclusion The marked increase in aggressive melanomas with associated metastasis, and the relatively high age at diagnosis, can partially explain the mortality.

Epidemiology and Risk Factors of Melanoma: A Review

We are currently witnessing a worldwide increase in the incidence of melanoma. Incidence in Europe is about 25 cases per 100,000 population, while in Australia it reaches a rate of 60 new cases per 100,000. While the epidemiological curves of the 1980's and 1990's suggested an increase in the incidence of melanoma across all age groups, the last 10 years’ data indicates a 5% reduction in the incidence of thin melanoma in young individuals aged between 15 and 24. This suggests a positive impact of primary prevention campaigns [1-2]. The risk factors associated with melanoma are different and multifactorial: on one hand, there is a genetic predisposition, as evidenced by the increased risk in patients with dysplastic nevus syndrome, with familial melanoma or familial melanoma syndromes; on the other hand, the unprotected interaction between UV rays and phototypes I-II increases the risk of developing melanoma, especially in case of sunburns in pediatric age. This review aims to summarize melanoma epidemiology and risk factors.

Towards Accurate Diagnosis of Skin Lesions Using Feedforward Back Propagation Neural Networks

In the automatic detection framework, there have been many attempts to develop models for real-time melanoma detection. To effectively discriminate benign and malign skin lesions, this work investigates sixty different architectures of the Feedforward Back Propagation Network (FFBPN), based on shape asymmetry for an optimal structural design that includes both the hidden neuron number and the input data selection. The reason for the choice of shape asymmetry was based on the 5–10% disagreement between dermatologists regarding the efficacy of asymmetry in the diagnosis of malignant melanoma. Asymmetry is quantified based on lesion shape (contour), moment of inertia of the lesion shape and histograms. The FFBPN has a high architecture flexibility, which indicates it as a favorable tool to avoid the over-parameterization of the ANN and, equally, to discard those redundant input datasets that usually result in poor test performance. The FFBPN was tested on four public image datasets containing melanoma, dysplastic nevus and nevus images. Experimental results on multiple benchmark data sets demonstrate that asymmetry A2 is a meaningful feature for skin lesion classification, and FFBPN with 16 neurons in the hidden layer can model the data without compromising prediction accuracy.

Discordance in Diagnosis of Melanocytic Lesions and Its Impact on Clinical Management

Context.— Accurate diagnosis of melanocytic lesions is fundamental for appropriate clinical management. Objective.— To evaluate the degree of discordance, if any, between histopathologic diagnoses of melanocytic lesions at referring institutions and at a tertiary referral cancer center and the potential impact of such discordance on clinical management. Design.— We retrospectively identified all patients referred to our comprehensive cancer center for evaluation of a melanocytic lesion from January 2010 to January 2011. For each patient, the histopathologic diagnosis from the referring institution was compared with the histopathologic diagnosis from a dermatopathologist at our center. Discordances were classified as major if they resulted in a change in clinical management and minor if they did not. Results.— A total of 1521 cases were included. The concordance rates were 72.2% (52 of 72) for dysplastic nevus, 75.0% (15 of 20) for all other types of nevi, 91.1% (143 of 157) for melanoma in situ, 96.1% (758 of 789) for invasive melanoma, and 99.6% (478 of 480) for metastatic melanoma. Major discordances were found in 20.2% of cases (307 of 1521), and minor discordances were found in 48.8% of cases (742 of 1521). Compared with the guideline-based treatment recommendation based on the referring-institution diagnosis, the guideline-based treatment recommendation based on the cancer center diagnosis was more extensive in 5.9% (89 of 1521) of patients and less extensive in 5.0% (76 of 1521) of patients. Conclusions.— Our findings underscore the importance of secondary histopathologic review of melanocytic lesions by expert dermatopathologists because significant changes in the diagnosis, tumor classification, and/or staging may be identified; thus, resulting in critical changes in recommendations for clinical management.

Excisional biopsy of a dysplastic nevus in a district polyclinic is a path to early detection of skin melanoma

Introduction. Russia has a high mortality rate of cutaneous melanoma – 2.5 per 100,000 population whereas the incidence rate is 7.7 per 100,000 population, i.e. one in every three patients dies. In the foreign countries (the USA, Australia), melanoma mortality rate is 10-15%. Such high rates are explained by the fact that patients with early-stage disease do not seek medical advice, as in early stages a tumour does not cause inconvenience to a patient and looks like an ordinary mole.The purpose of the study was to confirm the advisability of removing a progressive dysplastic nevus (grade 3 lentiginous melanocytic dysplasia) with a view to prevent and make early diagnosis of cutaneous melanoma.Materials and methods. The authors removed 180 pigmented lesions that were clinically diagnosed as a progressive dysplastic nevus in the Surgery Department of Central Polyclinic of Literary Fund from 2009 to March 2020. The patients were referred to the Surgery Department by physicians, dermatologists and other specialists of the polyclinic. Following an oncologist consultation, excisional biopsy of a nevus was performed under local anesthesia.Results. Histological examination revealed 29 (16%) dysplastic nevi with grade 3 LMD and 18 (10%) early-stage melanomas.Conclusions. If excisional biopsy of a dysplastic nevus becomes routine in Ambulatory Surgery practice, it will increase the early diagnosis of melanoma and significantly reduce mortality rates of this disease. For excisional biopsy, the authors recommend to excise at a distance of 0.5 to 1.0 cm from the lesion boundaries, since it is not possible to clinically distinguish a progressive dysplastic nevus from early melanoma.

Follow-up of melanocytic lesions with use of dermoscopy (literature review)

Regular follow-up is the most important preventive measure in patients with high risk for the development of melanoma. Particular attention is required for patients with dysplastic nevus syndrome, in which numerous lesions must be differentiated from malignant melanoma. General principles of monitoring of clinically atypical melanocytic lesions with the use of dermoscopy and indications for a diagnostic biopsy are discussed in the article.

Neurofibromatosis type 1 and melanoma of the iris arising from a dysplastic nevus: A rare yet casual association?

Purpose: We investigated the molecular causes of an unusual pigmented and ulcerated iris lesion detected in a patient diagnosed with neurofibromatosis type 1 (NF1). Case Report: A 52-year-old man was referred to our clinic with a non-traumatic ulcer in his left eye. Hyphema reabsorption disclosed a pigmented iris mass, thus ultrasound biomicroscopy and anterior segment fluorescein angiography were performed to investigate for the presence of a malignant lesion. Upon angiography, the lesion appeared highly vascularized but prevented posterior iris examination. Therefore, a gonioscopy was executed revealing extension of the lesion into the peripheral iris. Histopathology of the excisional iris biopsy revealed iris melanoma over a dysplastic nevus. NF1 is an autosomal dominant disorder characterized by pigmented cutaneous lesions, multiple skin tumors, and spinal and cranial nerve tumors. Uveal melanoma is the most common primary intraocular malignancy in adults. Up to 92% of cutaneous melanomas occur in patients with dysplastic nevus syndrome. Skin melanomas have been found in 0.1%–5.4% of NF1 patients. In literature, only 18 reports of uveal melanoma have been documented in association with NF1, including three cases of iris melanoma. Results: NF1 gene testing identified a causative mutation in the germline but no loss of the wild-type allele in the iris melanoma. Conclusions: Occurrence of both diseases in one patient is extremely rare, but the common origin of Schwann cells and melanoblasts suggests a non-casual association. Therefore, we propose that NF1 patients should be screened for nevi, both cutaneous and uveal, for better patients’ management.