Paediatric melanoma: clinical update, genetic basis, and advances in diagnosis

[Diagnosis of pediatric melanocytic tumors]

The histological diagnosis of pediatric melanocytic tumors is challenging, as benign nevi often resemble aggressive tumors. Accurate diagnosis is crucial for the early detection of rare pediatric melanomas. Recent advancements have established a classification based on genetic backgrounds. This classification distinguishes between rarer subtypes and includes groups such as conventional melanomas, Spitz tumors, and melanomas arising from congenital melanocytic nevi. While the most common group, Spitz tumors, generally has a favorable prognosis, conventional melanomas and especially those arising from congenital nevi may exhibit an aggressive course similar to that of adult melanoma.

Genetically predicted vitamins supplementation and risk of skin cancers: a Mendelian randomization study

BACKGROUND

The causal relationship between vitamins supplementation and the risk of skin cancers remains unclear. We conducted a Mendelian randomization study to assess the associations between vitamins supplementation and skin cancers in the general population.

OBJECTIVE

We aimed to investigate the causal relationship of vitamins (A-E) supplementation with skin cancers using and utilizing the linkage disequilibrium score regression (LDSC) Mendelian randomization (MR).

MATERIALS AND METHODS

We selected genome-wide significant single-nucleotide polymorphisms (SNPs) linked to vitamin supplements (A-E). Summary-level data for melanoma, basal cell carcinoma, and squamous cell carcinoma were obtained from large-scale genome-wide association studies. We applied the inverse-variance weighted (IVW) method within a random effects model, alongside weighted median, MR-Egger, simple median, sensitivity analyses, and MRlap methods to ensure robustness. A meta-analysis was conducted to assess the causal relationship between vitamins supplementation and melanoma. The STROBE-MR checklist was followed throughout.

RESULTS

Folate supplementation was associated with a reduced melanoma risk (IVW OR = 0.88; 95% CI 0.80-0.96; P = 0.006). The MR analysis indicated a significant inverse causal relationship. Heterogeneity and sensitivity analyses confirmed minimal impact from individual SNPs. MRlap corrected for potential estimation bias due to sample overlap, which was not significant, reinforcing the IVW findings. The meta-analysis ensured robust and stable results. LDSC regression analysis suggests a weak causal relationship between folate supplementation and melanoma. Yet no association was found between genetically predicted vitamins A, B6, B12, C, D, E, and skin cancers.

CONCLUSION

Both observational meta-analysis and MR analysis based on genetic variation provide robust evidence indicat that folate supplementation decreases the risk of melanoma, suggesting that interventions targeting folate supplementation may contribute to the primary prevention of melanoma. Further studies are needed to explore the potential association between other vitamins supplementation and the risk of skin cancers.

Comprehensive Breslow thickness (BT)-based analysis to identify biological mechanisms associated with melanoma pathogenesis

Breslow thickness (BT), a parameter measuring the depth of invasion of abnormally proliferating melanocytes, is a key indicator of melanoma severity and prognosis. However, the mechanisms underlying the increase in BT remain elusive. Utilizing data from The Cancer Genome Atlas (TCGA) human skin cutaneous melanoma (SKCM), we identified a set of BT-related molecules and analyzed their expression and genomic heterogeneity across pan-cancerous and normal tissues. Through consensus clustering, we identified two distinct BT phenotypes in melanoma, which exhibited significant differences in clinical, genomic, and immune infiltration characteristics. High BT molecular expression was associated with reduced CD8+ T cell infiltration and poor immunotherapy response, potentially mediated by the Macrophage Migration Inhibitory Factor (MIF) signaling pathway. In vitro experiments confirmed that BT molecules, including TRIM29, SERPINB5, and RAB25, promoted melanoma development through distinct mechanisms. Notably, fibroblast-derived TRIM29 and B-cell-derived RAB25 interacted with SPP1+ monocytes/macrophages via different pathways. Our findings suggest that genomic variations leading to imbalanced expression of BT molecules across cancers contribute to increased BT, which is closely linked to an immunosuppressive microenvironment. The involvement of multiple cell types and complex intercellular interactions underscores the importance of evaluating dynamic cellular crosstalk in the tumor microenvironment to better understand BT increases and develop more effective immunotherapeutic strategies.

A BEST classification system of large to giant congenital melanocytic nevi based on expert consensus and distribution characteristics

BACKGROUND

Large to giant congenital melanocytic nevi (LGCMN) significantly decrease patients' quality of life, but the inaccuracy of current classification system makes their clinical management challenging.

OBJECTIVES

To improve and extend the existing LGCMN 6B/7B classification systems by developing a novel LGCMN classification system based on a new phenotypic approach to clinical tool development.

METHODS

Three hundred and sixty-one LGCMN cases were categorized into four subtypes based on anatomic site: bonce (25.48%), extremity (17.73%), shawl (19.67%) and trunks (37.12%) LGCMN. A 'BEST' classification system of LGCMN was established and validated by a support vector machine classifier combined with the 7B system.

RESULTS

The most common LGCMN distributions were on bonce and trunks (bathing trunk), whereas breast/belly and body LGCMN were exceptionally rare. Sexual dimorphism characterized distribution, with females showing a wider range of lesions in the genital area. Nearly half of the patients with bathing trunk LGCMN exhibited a butterfly-like distribution. Approximately half of the LGCMN with chest involvement did not have nipple-areola complex involvement. Abdomen, back and buttock involvement was associated with the presence of satellite nevi (r = 0.558), and back and buttock involvement was associated with the presence of nodules (r = 0.364).

CONCLUSIONS

The effective quantification of a standardized anatomical site provides data support for the accuracy of the 6B/7B classification systems. The simplified BEST classification system can help establish a LGCMN clinical database for exploration of LGCMN aetiology, disease management and prognosis prediction.

Childhood and adolescent melanoma: An update

Pediatric melanoma is a rare but clinically significant public health concern, as it accounts for 7% of all malignancies in adolescents aged 15 to 19. Given the overall rarity of pediatric melanoma, especially in preadolescents, patients can go undetected, leading to a delay in treatment. We divide pediatric melanoma subtypes into three distinct age ranges-infantile, preadolescent, and adolescent-and distinguish the clinical features, prognosis, and associated risk factors of each age range. We next summarize the three predominant melanoma subtypes-Spitzoid melanoma, congenital melanocytic nevus-associated melanoma, and conventional (adult-type) melanoma-and provide distinguishing clinical, histologic, and genetic features from their difficult-to-differentiate benign counterparts. We conclude by reviewing consensus guidelines for pediatric melanoma staging and treatment, with a special emphasis on outlining barriers to adapting the advancements in targeted therapeutics into the standard care of pediatric melanoma.

Malignant melanoma with bone metastases in a child: a case report and review of literature

Introduction and importance

Melanoma is the fifth most common cancer diagnosed in the US in 2022. While its incidence increased from 1980 to 2017, it rarely happens in children. Its diagnosis and treatment are challenging in pediatric patients due to its rarity and different presentations compared to adults.

Case presentation

An 11.5-year-old boy with a complaint of back pain was admitted to the hospital. Initial examinations were normal; however, due to continued pain and symptoms (e.g., inability to walk, knee pain and ankle ecchymosis, weight loss, vomiting, nausea, and dyspnea), further examinations were performed. Biopsy, nuclear scan, computed tomography (CT) scan, and immunohistochemistry (IHC) confirmed the malignant melanoma diagnosis with bone and lung metastasis. Single-agent treatment with nivolumab was initiated after the diagnosis confirmation with no specific complication. The patient's parents decided to continue the treatment in their city of residence to reduce costs. However, the treatment was not continued, and unfortunately, the patient has passed away.

Clinical discussion

Melanoma is rare in children, making its diagnosis challenging. There are no specific guidelines for treating melanoma in pediatric patients, especially in children under 12, with ongoing debate on the most suitable treatment and follow-up options for these patients. It is important to fully examine resected legions for malignancy.

Conclusion

The study highlights the difficulties in diagnosing and treating malignant melanoma in children, considering its rarity and unusual signs and symptoms compared to adults. Specific guidelines are needed for diagnosing and treating malignant melanoma in pediatric patients.

Expression of the tumor antigens NY-ESO-1, tyrosinase, MAGE-A3, and TPTE in pediatric and adult melanoma: a retrospective case control study

Tumor-associated antigens (TAAs) are potential targets for T cell-based immunotherapy approaches in cutaneous melanoma. BNT111, an investigational lipoplex-formulated mRNA-based therapeutic cancer vaccine encoding melanoma TAAs NY-ESO-1, tyrosinase, MAGE-A3, and TPTE, is undergoing clinical testing in adults. Expression of these TAAs in pediatric melanoma is unclear but is a prerequisite for feasibility of this treatment approach in children with melanoma. Our main objective was to characterize expression of those TAAs in pediatric melanomas compared to control cohorts. In this retrospective case control study, protein and transcript expression of NY-ESO-1, tyrosinase, MAGE-A3, and TPTE were analyzed in a cohort of 25 pediatric melanomas, 31 melanomas of young adults, 29 adult melanomas, and 30 benign melanocytic nevi in children using immunohistochemical staining and digital pathology (QuPath) and reverse transcription quantitative PCR. Based on IHC analysis, pediatric melanomas expressed tyrosinase (100.0%), TPTE (44.0%), MAGE-A3 (12.0%), and NY-ESO-1 (8.0%). Young adult melanomas expressed tyrosinase (96.8%), NY-ESO-1 (19.4%), MAGE-A3 (19.4%), and TPTE (3.2%). Adult melanomas expressed tyrosinase (86.2%), MAGE-A3 (75.9%), NY-ESO-1 (48.3%), and TPTE (48.3%). Childhood melanocytic nevi only expressed tyrosinase (93.3%). Expression prevalence of individual TAAs did not differ between subtypes of pediatric melanoma, and no association with prognosis was found. All four TAAs were expressed in pediatric melanoma, albeit NY-ESO-1 and MAGE-A3 to a lesser extent than in adult melanoma. These data support the possibility of investigating vaccines targeting these TAAs for the treatment of pediatric melanoma.

Characterization of PRAME immunohistochemistry reveals lower expression in pediatric melanoma compared to adult melanoma

Pediatric melanomas are rare tumors that have clinical and histological differences from adult melanomas. In adult melanoma, the immunohistochemical marker PRAME is increasingly employed as a diagnostic adjunct. PRAME is also under investigation as a target structure for next-generation immunotherapies including T-cell engagers. Little is known about the characteristics of PRAME expression in pediatric melanoma. In this retrospective study, samples from 25 pediatric melanomas were compared with control groups of melanomas in young adults (18-30 years; n = 32), adult melanoma (>30 years, n = 30), and benign melanocytic nevi in children (0-18 years; n = 30) with regard to the immunohistochemical expression of PRAME (diffuse PRAME expression >75%/absolute expression). Pediatric melanomas show lower diffuse PRAME expression (4%) and lower absolute PRAME expression (25%) compared to young adult melanomas (15.6%/46.8%) and adult melanomas (50%/70%). A significant age-dependent expression could be observed. An analysis of event-free survival shows no prognostic role for PRAME in pediatric melanoma and young adult melanoma, but a significant association with diffuse PRAME expression in adulthood. The age dependency of PRAME expression poses a potential pitfall in the diagnostic application of melanocytic tumors in young patients and may limit therapeutic options within this age group. The immunohistochemical expression of the tumor-associated antigen PRAME is an increasingly important diagnostic marker for melanocytic tumors and is gaining attention as a possible immunotherapeutic target in melanoma. As the available data primarily stem from adult melanoma, and given the clinical and histological distinctions in pediatric melanomas, our understanding of PRAME expression in this specific patient group remains limited. The age-dependent low PRAME expression shown here constrains the use of this marker in pediatric melanoma and may also limit the use of immunotherapeutic strategies against PRAME in young patients.

Diagnostic and Therapeutic Challenges in Pediatric Cutaneous Melanoma: Two Case Reports From the Moroccan Population

Although cutaneous melanoma (CM) is one of the most prevalent cancers in adults, it is rarely reported in children. Often, the diagnosis is delayed and difficult to make. We presented two novel examples of pediatric CM from the Department of Pediatric Plastic Surgery Unit at Rabat Children's Hospital. The first case included a 14-year-old girl who had a cutaneous nodule on her right leg. She first came with an inguinal enlargement, for which a lymph node biopsy was positive. A further inguinal dissection of 10 lymph nodes revealed four metastatic ones (4N+\10N). She received a wide local excision of the lesion, which revealed nodular melanoma with an 8 mm thickness as determined by Breslow, as well as safe lateral and deep margins. The course was distinguished by the emergence of new metastatic lymph node locations, and the patient died a few weeks later. The second case included a 13-year-old girl who appeared with a cutaneous lesion centered on a scar on her right leg. She also underwent a large local excision, which revealed nodular melanoma with a thickness of 12 mm according to Breslow, as well as complete lateral and deep excisions. Her follow-up revealed favorable results, with no local recurrence or distant metastases. This case series emphasized the difficult management of two separate occurrences of pediatric CM. We also emphasized the importance of early detection of suspicious lesions, regular follow-ups, and raising awareness among high-risk patients.

Regional lymph node evaluation in pediatric conventional melanoma subtype: a single-center 10-year review

PURPOSE

To assess the prognostic and therapeutic significance of sentinel lymph node biopsy (SLNB) and completion lymph node dissection (CLND) in pediatric conventional melanoma (CM), while evaluating potential predictive factors for outcomes.

METHODS

We conducted a retrospective analysis of medical records spanning 2009-2020, focusing on patients aged 18 or younger with localized cutaneous conventional melanoma.

RESULTS

Among the 33 patients, SLNB detected metastasis in 57.6% of cases, with 52.6% undergoing CLND. Positive SLN patients had higher relapse risk (HR 5.92; 95% CI 1.27-27.7; P = 0.024) but similar overall survival (HR 3.19; 95% CI 0.31-33.1, P = 0.33). No significant differences in disease-free survival (DFS) and OS were found between patients who underwent CLND and those who did not (HR 1.91; 95% CI 0.49-7.43, P = 0.35, and HR 0.52; 95% CI 0.03-8.32, P = 0.64, respectively). Univariate analysis showed age at diagnosis (P = 0.02) correlated with higher recurrence risk, with a 21% hazard increase per additional year of age.

CONCLUSIONS

Positive SLN status and age at diagnosis were associated with worse DFS in CM patients. Our study did not find any prognostic or therapeutic value in CLND for pediatric melanoma. Further multicenter trials are needed to confirm our single-institution experience.

LEVEL OF EVIDENCE

Level IV.

Oral mucosa involvement in pediatric patients with xeroderma pigmentosum: a comprehensive review

BACKGROUND

Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder presenting with an inability to repair UV-induced DNA damage. This can lead to the development of neoplasms affecting multiple organ systems, with onset often in childhood. Unfortunately, no cure currently exists for XP, and management strategies focus on sun protection and early intervention for malignancies. Although most skin problems in XP patients are UV induced, various oral lesions are also described. However, the literature has not extensively characterized the oral manifestations and their prognostic significance.

METHODS

We conducted a comprehensive review to evaluate the prevalence and nature of oral mucosal lesions in pediatric XP patients.

RESULTS

Our literature search yielded 130 pediatric XP patients with oral involvement and 210 associated tumoral or non-tumoral lesions. Squamous cell carcinoma was the most common type of oral mucosal tumor reported, with other malignancies including basal cell carcinoma, melanoma, angiosarcoma, fibrosarcoma, and trichilemmal carcinoma.

CONCLUSION

Given the potential morbidity and mortality associated with oral mucosal tumors in XP patients, our study aims to raise awareness of these manifestations. Early diagnosis and treatment are crucial for managing these lesions effectively, and routine oral exams should be considered a critical component of dermatological evaluations for XP patients, especially in the pediatric age group.

Hematopoietic colony-stimulating factors in head and neck cancers: Recent advances and therapeutic challenges

Colony-stimulating factors (CSFs) are key cytokines responsible for the production, maturation, and mobilization of the granulocytic and macrophage lineages from the bone marrow, which have been gaining attention for playing pro- and/or anti-tumorigenic roles in cancer. Head and neck cancers (HNCs) represent a group of heterogeneous neoplasms with high morbidity and mortality worldwide. Treatment for HNCs is still limited even with the advancements in cancer immunotherapy. Novel treatments for patients with recurrent and metastatic HNCs are urgently needed. This article provides an in-depth review of the role of hematopoietic cytokines such as granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage colony-stimulating factor (M-CSF), and interleukin-3 (IL-3; also known as multi-CSF) in the HNCs tumor microenvironment. We have reviewed current results from clinical trials using CSFs as adjuvant therapy to treat HNCs patients, and also clinical findings reported to date on the therapeutic application of CSFs toxicities arising from chemoradiotherapy.

Pembrolizumab Versus High-Dose Interferon-α2b as Adjuvant Therapy for Pediatric Melanoma: A Retrospective Study

INTRODUCTION

Pembrolizumab is well-tolerated in pediatric patients with advanced tumors, consistent with results in adults. However, information on the safety and efficacy of adjuvant pembrolizumab in children and adolescents with melanoma is lacking.

OBJECTIVES

To compare pembrolizumab versus high-dose interferon-α2b (HDI) as adjuvant therapy in pediatric patients with melanoma.

METHODS

We performed a retrospective study of pediatric patients diagnosed with melanoma between January 2008 and April 2022. Relapse-free survival (RFS) and the 1-year RFS rate were compared between patients receiving adjuvant pembrolizumab or HDI.

RESULTS

Seventy-five pediatric patients with melanoma were screened from a database of 6,013 patients. Twenty-four patients were finally enrolled, of whom 9 received pembrolizumab and 15 received HDI as adjuvant therapy. By August 31, 2022, the median follow-up times were 23.6 months and 98.7 months in the pembrolizumab and HDI groups, respectively. There was no significant difference in median RFS between two groups (not reached versus 38.7 months, P = 0.11). The median overall survival was not reached in either group. The 1-year RFS rates were 88.9% and 66.7% in the pembrolizumab and HDI groups, respectively. All adverse events in the pembrolizumab group were grade 1 or 2, but grade 3-5 adverse events occurred in two (13%) patients receiving HDI.

CONCLUSIONS

RFS was similar in pediatric patients with melanoma receiving adjuvant pembrolizumab or HDI, but pembrolizumab was associated with a reduced risk of recurrence and a more favorable safety profile. However, due to the small sample size and differences in follow-up time, larger and prospective studies are still warranted to explore better adjuvant therapies for pediatric melanoma.

Masquerading Spitz naevi on the upper lip: A case report with a brief review of the literature

In a scenario where there is an increased incidence of oral squamous cell carcinoma (OSCC) in younger age groups, the diagnosis of pseudo-malignant lesions that mimic the histopathology of a moderate or even high-grade carcinoma becomes imperative for oral pathologists. Though paediatric malignancies such as melanomas and thyroid carcinomas and even OSCCs have been reported in young children, they are rare in the pre-pubertal age group. Melanocytic naevi such as Spitz naevi (SNs) or atypical SNs is, however, more common in this age group and could create some difficulty in diagnosis due to its histological variations that could mimic a malignancy. Hence, the need for a cautious correlation between clinical and histopathological features becomes manifold. Adjunct tools that use diagnostic and molecular techniques such as immunohistochemistry (IHC) and comparative genomic hybridisation (CGH) help in diagnosis and in differentiating certain types of SNs from Spitzoid melanomas or melanomas. A case that histopathologically resembled a moderately differentiated squamous cell carcinoma without any evidence of melanocytic content proved to be a melanocytic naevus after clinical correlation of both age and immunohistochemical analysis. This case report with review brings to light the importance of being aware of such pseudo-malignant lesions in our daily practice.

Metastatic Melanoma in Young Child

Pediatric melanoma is a rare cancer, especially in young children, and it remains a diagnostic challenge. We report a case of massively metastatic melanoma in young patient with an atypical clinical and biological presentation and with no risk factors.

Pediatric spitzoid lesions of the ear: a single-center experience and review of the literature

Spitzoid lesions are challenging melanocytic lesions comprising benign, intermediate, and malignant lesions. In this study, we aimed to analyze the diagnostic accuracy of clinical and dermatoscopical evaluations of pediatric spitzoid ear lesions. We collected and analyzed, clinically, dermatoscopically, and histologically, pediatric spitzoid ear lesions. We also conducted a systematic review of the literature. At the Pediatric Hospital Gaslini, excision and histopathological evaluation were performed on eight cases: 87.5% of the lesions were consistent with Spitz nevus (SN), and 12.5% with atypical Spitz tumor (AST). Notably, multiple (≥2) dermatoscopical irregularities were present in 5 of 7 SN (71%), yet none were found in AST (0%, 0/1) (Fisher's exact test, P=0.375). From systematic research in the literature, 9 patients were included in this review. At histology, 88.9% were SN and 11% AST. Remarkably, also in the literature, multiple dermatoscopical irregularities were present in most SN (75%, 6/8), but not in the identified AST (0%, 0/1) (P=0.3333). We present a monocentric study on pediatric spitzoid ear lesions. Importantly, dermatoscopical irregularities were not significantly associated with AST, neither in our series nor in the reviewed literature (respectively P=0.375 and P=0.3333), supporting the fact that relying only on the dermatoscopical aspect of spitzoid lesions is not accurate enough for the special site of the ear, where dermatoscopy could actually be misleading.

LSM2 is associated with a poor prognosis and promotes cell proliferation, migration, and invasion in skin cutaneous melanoma

BACKGROUND

Skin cutaneous melanoma (SKCM) is an extremely malignant tumor that is associated with a poor prognosis. LSM2 has been found to be related to different types of tumors; however, its role in SKCM is poorly defined. We aimed to determine the value of LSM2 as a prognostic biomarker for SKCM.

METHODS

The expression profile of LSM2 mRNA was compared between tumor and normal tissues in public databases, such as TCGA, GEO, and BioGPS. LSM2 protein expression was explored using immunohistochemistry (IHC) on a tissue microarray containing 44 SKCM tissues and 8 normal samples collected at our center. Kaplan-Meier analysis was performed to assess the prognostic value of LSM2 expression in patients with SKCM. SKCM cell lines with LSM2 knockdown were used to determine the effects of LSM2. Cell counting kit-8 (CCK8) and colony formation assays were conducted to assess cell proliferation, whereas wound healing and transwell assays were carried out to assess the migration and invasion abilities of SKCM cells.

RESULTS

LSM2 was more highly expressed at the mRNA and protein levels in SKCM than that in normal skin. Moreover, elevated expression of LSM2 was associated with shorter survival time and early recurrence in patients with SKCM. The in vitro results revealed that the silencing of LSM2 in SKCM cells significantly inhibited cell proliferation, migration, and invasion.

CONCLUSION

Overall, LSM2 contributes to malignant status and poor prognosis in patients with SKCM and may be identified as a novel prognostic biomarker and therapeutic target.

The role of fibroblast growth factor 18 in cancers: functions and signaling pathways

Fibroblast growth factor 18(FGF18) is a member of the fibroblast growth factor family (FGFs). FGF18 is a class of bioactive substances that can conduct biological signals, regulate cell growth, participate in tissue repair and other functions, and can promote the occurrence and development of different types of malignant tumors through various mechanisms. In this review, we focus on recent studies of FGF18 in the diagnosis, treatment, and prognosis of tumors in digestive, reproductive, urinary, respiratory, motor, and pediatric systems. These findings suggest that FGF18 may play an increasingly important role in the clinical evaluation of these malignancies. Overall, FGF18 can function as an important oncogene at different gene and protein levels, and can be used as a potential new therapeutic target and prognostic biomarker for these tumors.

Is Pediatric Melanoma Really That Different from Adult Melanoma? A Multicenter Epidemiological, Clinical and Dermoscopic Study

PURPOSE

To improve the diagnostic accuracy and optimal management of pediatric melanomas.

METHODS

We conducted a retrospective descriptive, multicenter study of the epidemiological, clinical, and dermoscopic characteristics of histopathologically proven melanomas diagnosed in patients less than 18 years old. Data on sociodemographic variables, clinical and dermoscopic characteristics, histopathology, local extension, therapy and follow-up, lymph node staging, and outcome were collected from the databases of three Italian dermatology units. We performed a clinical evaluation of the morphological characteristics of each assessed melanoma, using both classic ABCDE criteria and the modified ABCDE algorithm for pediatric melanoma to evaluate which of the two algorithms best suited our series.

RESULTS

The study population consisted of 39 patients with a histologically confirmed diagnosis of pediatric melanoma. Comparing classic ABCDE criteria with the modified ABCDE algorithm for pediatric melanomas, the modified pediatric ABCDE algorithm was less sensitive than the conventional criteria. Dermoscopically, the most frequent finding was the presence of irregular streaks/pseudopods (74.4%). When evaluating the total number of different suspicious dermoscopy criteria per lesion, 64.1% of the lesion assessments recognized two dermoscopic characteristics, 20.5% identified three, and 15.4% documented four or more assessments.

CONCLUSIONS

Contrary to what has always been described in the literature, from a clinical point of view, about 95% of our cases presented in a pigmented and non-amelanotic form, and these data must be underlined in the various prevention campaigns where pediatric melanoma is currently associated with a more frequently amelanotic form. All the pediatric melanomas analyzed presented at least two dermoscopic criteria of melanoma, suggesting that this could be a key for the dermoscopic diagnosis of suspected pediatric melanoma, making it possible to reach an early diagnosis even in this age group.

Increased incidence of melanoma in children and adolescents in Finland in 1990-2014: nationwide re-evaluation of histopathological characteristics

BACKGROUND

Changes in the incidence of melanoma in children and adolescents have been reported in Europe and in the USA in the recent decades.

AIMS

The aim of this study was to examine the incidence of paediatric and adolescent melanomas in Finland in 1990-2014, and the associated clinical and histopathological characteristics to reveal temporal trends, such as changes in diagnostic sensitivity of Spitzoid melanomas.

METHODS

Information on 122 patients diagnosed with cutaneous melanoma at 0-19 years of age in Finland in 1990-2014 were retrieved from the Finnish Cancer Registry. 73 primary melanoma archival samples were re-evaluated by two dermatopathologists to allow comparability over time.

RESULTS

A 5.6% annual increase was observed in the incidence of melanoma among children and adolescents during the study period. Fifty-six tumours were confirmed as malignant melanomas in the re-evaluation. After correction for tumour misclassification in the Cancer Registry, the age-adjusted annual incidence was estimated to have increased from 1.4/1 000 000 in 1990-1994 to 5.8/1 000 000 in 2010-2014. The change in incidence was most prominent among adolescents and in Spitzoid melanoma subtype. Melanomas diagnosed 1990-2002 and 2003-2014 did not differ in terms of their clinicopathological characteristics or prognosis (hazard ratio for melanoma-related death 1.53, 95% CI 0.30 to 7.88). Spitzoid melanomas were diagnosed at a younger age, were of higher stage and had higher Clark level than other melanomas, yet the hazard ratio for death was 0.52 (95% CI 0.10 to 2.58) for Spitzoid versus other melanomas.

CONCLUSIONS

The incidence of cutaneous melanoma has clearly increased among the young in Finland, especially among adolescents. No evidence for overdiagnosis of Spitzoid melanomas as the underlying cause of the increased incidence was observed.Key messageA nationwide retrospective re-evaluation of the cutaneous melanomas recorded in the Finnish Cancer Registry among patients aged 0-19 years in Finland in 1990-2014 revealed an approximately 4-fold increase in the incidence. The increase in the incidence was most prominent among adolescents and in the Spitzoid melanoma subtype. Our results contrast those reported in other countries, where the incidence of melanoma among adolescents has declined.

Long Noncoding RNA LINC02249 Is a Prognostic Biomarker and Correlates with Immunosuppressive Microenvironment in Skin Cutaneous Melanoma

Skin cutaneous melanoma (SKCM) is one of the most aggressive and life-threatening tumors. It has a high incidence rate, as well as significant metastasis and fatality rates. To successfully treat SKCM and to increase the overall survival rate, early identification and risk stratification are both absolutely necessary. Long noncoding RNAs (lncRNAs) play a significant regulatory role in a variety of cancers. However, the expression and function of many lncRNAs have not been investigated. We evaluated the expression profile of the long noncoding RNA LINC02249 (LINC02249) in pan-cancers by using data on gene expression obtained from TCGA and GTEx. The biological function of LINC02249 was determined by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). The prognostic value of LINC02249 expression in SKCM patients was statistically analyzed. Besides, the ssGSEA approach was utilized in order to investigate the degree to which LINC02249 expression is correlated with tumor immune infiltration. In this study, the expression of LINC02249 was found to be abnormally high in a variety of tumors, according to our findings. When compared with nontumor specimens, the level of expression of LINC02249 was shown to be significantly elevated in SKCM samples. GO and KEGG assays revealed LINC02249 may be involved in tumor progression. High expression of LINC02249 was associated with shorter overall survival and disease-specific survival of SKCM patients. More importantly, multivariate methods revealed that LINC02249 expression was an independent prognostic factor for SKCM cases. Using ssGSEA, we found that the expression of LINC02249 was negatively associated with different tumor-infiltrating immune cells, especially aDC, Treg, and macrophages. Overall, our findings suggested that LINC02249 can serve as a novel biomarker to predict the prognosis and immune infiltration in SKCM.

Dermatoscopic and clinical features of congenital or congenital-type nail matrix nevi: A multicenter prospective cohort study by the International Dermoscopy Society

BACKGROUND

Congenital nail matrix nevi (NMN) are difficult to diagnose because they feature clinical characteristics suggestive of adult subungual melanoma. Nail matrix biopsy is difficult to perform, especially in children.

OBJECTIVE

To describe the initial clinical and dermatoscopic features of NMN appearing at birth (congenital) or after birth but before the age of 5 years (congenital-type).

METHODS

We conducted a prospective, international, and consecutive data collection in 102 hospitals or private medical offices across 30 countries from 2009 to 2019.

RESULTS

There were 69 congenital and 161 congenital-type NMNs. Congenital and congenital-type NMN predominantly displayed an irregular pattern of longitudinal microlines (n = 146, 64%), reminiscent of subungual melanoma in adults. The distal fibrillar ("brush-like") pattern, present in 63 patients (27.8%), was more frequently encountered in congenital NMN than in congenital-type NMN (P = .012). Moreover, congenital NMN more frequently displayed a periungual pigmentation (P = .029) and Hutchinson's sign (P = .027) than did congenital-type NMN.

LIMITATIONS

Lack of systematic biopsy-proven diagnosis and heterogeneity of clinical and dermatoscopic photographs.

CONCLUSION

Congenital and congenital-type NMN showed worrisome clinical and dermatoscopic features similar to those observed in adulthood subungual melanoma. The distal fibrillar ("brush-like") pattern is a suggestive feature of congenital and congenital-type NMN.

Melanoma in children and adolescents: analysis of susceptibility genes in 123 Italian patients

BACKGROUND

A polygenic inheritance involving high, medium and low penetrance genes has been suggested for melanoma susceptibility in adults, but genetic information is scarce for paediatric patients.

OBJECTIVE

We aim to analyse the major high and intermediate melanoma risk genes, CDKN2A, CDK4, POT1, MITF and MC1R, in a large multicentre cohort of Italian children and adolescents in order to explore the genetic context of paediatric melanoma and to reveal potential differences in heritability between children and adolescents.

METHODS

One-hundred-twenty-three patients (<21 years) from nine Italian centres were analysed for the CDKN2A, CDK4, POT1, MITF, and MC1R melanoma predisposing genes. The rate of gene variants was compared between sporadic, familial and multiple melanoma patients and between children and adolescents, and their association with clinico-pathological characteristics was evaluated.

RESULTS

Most patients carried MC1R variants (67%), while CDKN2A pathogenic variants were found in 9% of the cases, the MITF E318K in 2% of patients and none carried CDK4 or the POT1 S270N pathogenic variant. Sporadic melanoma patients significantly differed from familial and multiple cases for the young age at diagnosis, infrequent red hair colour, low number of nevi, low frequency of CDKN2A pathogenic variants and of the MC1R R160W variant. Melanoma in children (≤12 years) had more frequently spitzoid histotype, were located on the head/neck and upper limbs and had higher Breslow thickness. The MC1R V92M variant was more common in children than in adolescents. CDKN2A common polymorphisms and MC1R variants were associated with a high number of nevi.

CONCLUSION

Our results confirm the scarce involvement of the major high-risk susceptibility genes in paediatric melanoma and suggest the implication of MC1R gene variants especially in the children population.

Differences in individual and environmental factors between cutaneous melanoma and atypical Spitz tumour in children and adolescents

It is not known if children and adolescents with atypical Spitz tumour and cutaneous melanoma differ in terms of etiological factors. The aim of this study was to explain differences in individual and environmental factors between cutaneous melanoma and atypical Spitz tumour. In the context of a study on melanocytic lesions, all subjects aged under 20 years with either cutaneous melanoma or atypical Spitz tumour were included (N = 105). Information on socio-demographic characteristics, individual and environmental factors were collected for both mother and child. The Fisher's exact test and the Mann-Whitney U test were used for categorical variables and continuous variables respectively. A multivariate logistic model was used to explain differences in outcome by differences in explanatory variables. In comparison to patients with cutaneous melanoma, patients with atypical Spitz tumour had less freckles (p = 0.020), lower number of common nevi (p = 0.002), and lower body mass index (p = 0.001) and experienced less sunburns episodes (p = 0.008). However, in the multivariate analysis, only a low number of common nevi remained statistically significant. Children and adolescents with cutaneous melanoma have a high number of nevi in comparison to the same-age group with atypical Spitz tumour.Conclusion: The results of this study suggest that the only difference in individual and environmental risk factors between cutaneous melanoma and atypical Spitz tumour in children and adolescents is the number of nevi. What is Known: •Atypical Spitz tumours and cutaneous melanoma in children and adolescents are clinically similar, but compared with melanoma, they have a good overall prognosis. •Risk factors for cutaneous melanoma in children and adolescents are similar to the ones found in adults in the literature What is New: •Differences in individual and environmental risk factors for atypical Spitz tumour in children and adolescents are described for the first time in this study. •Individual and environmental factors for atypical Spitz tumour in children and adolescents are comparable to cutaneous melanoma, except for the presence of low number of nevi.

Immunotherapy in Adolescents and Young Adults: What Remains in Cancer Survivors?

Immunotherapy has changed the landscape of treatments for advanced disease in multiple neoplasms. More and more patients are long survivors from a metastatic disease. Most recently, the extension of indications and evidence of efficacy in early disease settings, such as the adjuvant and neoadjuvant setting in breast cancer, lung cancer, glioma, and gastric cancer, places more attention on what happens to patients who survive cancer. In particular, we evaluated what happens in young patients, a population in whom some immune-related effects are still poorly described. Immunotherapy is already a reality in early disease settings and the scientific community is lagging in describing what to expect in adolescent and young adult (AYA) patients. For instance, the impact of these therapies on female and male fertility is not clear, similarly to the interaction that may occur between these drugs and pregnancy. This review aims to highlight these little-known topics that are difficult to evaluate in ad hoc studies.

THE demographics and trends in pediatric melanoma in the United States: An analysis of the National Cancer Database

BACKGROUND/OBJECTIVE

Relative to adults, rates of melanoma are lower in children. Due to its rarity, it is difficult to assess the incidence, trends, and outcomes of this malignancy. Much of our understanding comes from single institution or regional cancer registries which may not be large enough to detect subtleties in the burden of pediatric melanoma.

METHODS

Data from the 2004 to 2016 National Cancer Database were analyzed; this database captures approximately 70% of all cancer diagnoses in the United States.

RESULTS

Our analysis consisted of 1903 cases. A majority were White (89.8%), the mean age was 12.4 years, and the ratio of females: males was 1.2:1.0. The most common anatomic location was the trunk (31.1%). Between 2004 and 2016, a decreasing trend in the number of new melanoma cases was observed. Comparing histologic subtype by age, there was an increased percentage of nodular and epithelioid and spindle cell tumors in the pre-teen children and a greater percentage of superficial spreading tumors in teenagers. Overall, a majority of cases were stage 0 or I (56.9%), with relatively few stage IV cases (2.0%). A 5-year all-cause survival of greater than 90% was observed for stage I-III tumors, with stage IV tumors having a 5-year all-cause survival of 34.4%.

CONCLUSION

Comparable to previous studies, pediatric melanoma occurred most often in Whites, females, and adolescents. However, we detected a decreasing trend in new cases, noted differences between histologic subtype and age, and observed a 5-year all-cause survival rate of greater than 90% for stage I-III tumors.

Clinical and dermoscopic characterization of pediatric Spitz nevi of the ear

Spitz nevi of special sites, such as the ear, appear rarely and pose a challenge with worrisome clinical, dermoscopic, or histopathological features. Our aim was to evaluate the morphological findings of a series of Spitz nevi of the ear in order to obtain more knowledge about their clinical-dermoscopic patterns. Of a total of six cases, three main dermoscopic structures were found: pseudonetwork, structureless areas, and cobblestone pattern. Our preliminary findings suggest that dermoscopy may be helpful in improving the diagnostic accuracy of Spitz nevus of the ear and minimize surgery in a sensitive location.

Neurocutaneous melanocytosis (melanosis)

Neurocutaneous melanosis (NCM; MIM # 249400; ORPHA: 2481], first reported by the Bohemian pathologist Rokitansky in 1861, and now more precisely defined as neurocutaneous melanocytosis, is a rare, congenital syndrome characterised by the association of (1) congenital melanocytic nevi (CMN) of the skin with overlying hypertrichosis, presenting as (a) large (LCMN) or giant and/or multiple (MCMN) melanocytic lesions (or both; sometimes associated with smaller "satellite" nevi) or (b) as proliferative melanocytic nodules; and (2) melanocytosis (with infiltration) of the brain parenchyma and/or leptomeninges. CMN of the skin and leptomeningeal/nervous system infiltration are usually benign, more rarely may progress to melanoma or non-malignant melanosis of the brain. Approximately 12% of individuals with LCMN will develop NCM: wide extension and/or dorsal axial distribution of LCMN increases the risk of NCM. The CMN are recognised at birth and are distributed over the skin according to 6 or more patterns (6B patterns) in line with the archetypical patterns of distribution of mosaic skin disorders. Neurological manifestations can appear acutely in infancy, or more frequently later in childhood or adult life, and include signs/symptoms of intracranial hypertension, seizures/epilepsy, cranial nerve palsies, motor/sensory deficits, cognitive/behavioural abnormalities, sleep cycle anomalies, and eventually neurological deterioration. NMC patients may be symptomatic or asymptomatic, with or without evidence of the typical nervous system changes at MRI. Associated brain and spinal cord malformations include the Dandy-Walker malformation (DWM) complex, hemimegalencephaly, cortical dysplasia, arachnoid cysts, Chiari I and II malformations, syringomyelia, meningoceles, occult spinal dysraphism, and CNS lipoma/lipomatosis. There is no systemic involvement, or only rarely. Pathogenically, single postzygotic mutations in the NRAS (neuroblastoma RAS viral oncogene homologue; MIM # 164790; at 1p13.2) proto-oncogene explain the occurrence of single/multiple CMNs and melanocytic and non-melanocytic nervous system lesions in NCM: these disrupt the RAS/ERK/mTOR/PI3K/akt pathways. Diagnostic/surveillance work-ups require physical examination, ophthalmoscopy, brain/spinal cord magnetic resonance imaging (MRI) and angiography (MRA), positron emission tomography (PET), and video-EEG and IQ testing. Treatment strategies include laser therapy, chemical peeling, dermabrasion, and surgical removal/grafting for CMNs and shunt surgery and surgical removal/chemo/radiotherapy for CNS lesions. Biologically targeted therapies tailored (a) BRAF/MEK in NCM mice (MEK162) and GCMN (trametinib); (b) PI3K/mTOR (omipalisib/GSK2126458) in NMC cells; (c) RAS/MEK (vemurafenib and trametinib) in LCMNs cells; or created experimental NMC cells (YP-MEL).

[Early-onset melanoma (congenital, neonatal, infantile): A systematic review of literature cases]

INTRODUCTION

Neonatal and infantile malignant melanoma is rare. It may be difficult to diagnose and often carries a poor prognosis.

MATERIAL AND METHODS

We decided to review the data on congenital, neonatal and infantile malignant melanomas in order to understand their presentation (clinical, histological, molecular), diagnosis, management and outcomes. We performed a literature search of all cases of early-onset melanoma published in PubMed from its inception to March 2019 using the following keywords: "malignant melanoma" OR "melanoma" OR "pigmented nevus" OR "malignant pigmented" AND "infantile" OR "congenital" OR "children" OR "childhood" OR "infancy" OR "neonatal". Congenital melanoma associated with maternal-foetal transmission was not included in the study.

RESULTS

Sixty-five articles were selected and 85 cases were included in the study. Most patients were male (sex ratio: 1.6). The average age at diagnosis was 5.5 months (minimum-maximum: 0-24 months). The main site reported for congenital melanoma was the head-and-neck area and for neonatal and infantile melanoma the trunk. Half of all patients had a metastatic disease at the time of diagnosis. In metastatic cases, the prognosis was poor with the exception of patients undergoing complete excision of the tumour and metastases. The main treatment for cutaneous melanomas and operable metastasis was surgery, and secondarily, chemotherapy/immunotherapy.

CONCLUSION

Neonatal and infantile malignant melanoma are rarely reported and not well-documented. It is necessary to collect additional cases to improve our knowledge of this rare disease.