Update on melanocytic nevi in children

Epidemiological characteristics and hospitalization burden analysis of pediatric inpatients with melanocytic nevi in China from 2016 to 2021: A nationwide retrospective study of 13,396 cases

BACKGROUND

Melanocytic nevi typically appear in early childhood, and their removal is a common plastic surgery procedure performed on children. However, the epidemiological characteristics and hospitalization burden of children with melanocytic nevi have rarely been described in detail.

METHODS

Medical records of pediatric inpatients with melanocytic nevi from January 1, 2016, to December 31, 2021, were collected from the Futang Research Center of Pediatric Development database in China. We then extracted and statistically analyzed the relevant information, including demographic characteristics, clinical information, hospitalization burden, and other basic information for each inpatient.

RESULTS

Among the 13,396 inpatients with melanocytic nevi, the highest number of cases was found in East China, and most patients were residents of urban areas. Most hospitalized patients consisted of boys aged 7-12 years with melanocytic nevi. Lesion sites in the buttocks and lower limbs were most common among pediatric inpatients with melanocytic nevi. Compound nevi were the most common (38.50 %) histological subtype and the rate of conversion into melanoma was 1.02 % (137 inpatients) among pediatric inpatients with melanocytic nevi. The hospitalization burden for patients varied significantly based on factors such as the age of the patients undergoing surgery, year of hospitalization, site of the lesion, histological subtype, and surgical method. In general, if the patients' age was under 1 year, lesion site was located in face, and there was a need for excision combined with tissue expander can significantly increase the treatment fees for pediatric inpatients with melanocytic nevi.

CONCLUSION

Given the increasing number and relatively large hospitalization burden among children with melanocytic nevi hospitalized in China, the government needs to pay more attention to this group and provide corresponding economic and policy support.

Pigmented Epithelioid Melanocytoma of the Penis: A Case Report

Pigmented epithelioid melanocytoma is rare cutaneous melanocytic proliferation, characterized by heavily pigmented melanocytes, with a potential for regional node metastasis, but with an overall favorable clinical course. Here, we describe an uncommon case of pigmented epithelioid melanocytoma involving the penis in an adolescent patient.

Application of dermoscopy and reflectance confocal microscopy in vivo in the evaluation of nevi in children

BACKGROUND

Melanocytic nevi are frequently observed in the pediatric population. While newly acquired nevi can appear during childhood, congenital nevi can continue to grow and clinically change, making patient caregivers concerned. Reflectance confocal microscopy (RCM) in vivo is a noninvasive tool that might enhance the diagnostic accuracy of dermoscopy, reducing the rate of unnecessary surgical procedures. This study aimed to assess the utility of RCM in increasing the diagnostic accuracy of pediatric melanocytic nevi that show pigmentation changes or grow rapidly.

METHODS

Pediatric patients who presented between January 2022 and February 2023 in a single institution with rapidly growing melanocytic nevi or nevi that presented changes in the pigmentation were included in the study. All nevi were evaluated by means of dermoscopy and RCM.

RESULTS

Forty-two patients with a total of 42 melanocytic nevi were included. Most lesions showed a honeycombed pattern (n = 21, 50%). On RCM, only 3 of 42 nevi presented atypical cells within the epidermis (7.1%). Evaluation of the dermoepidermal junction (DEJ) revealed the predominance of the meshwork pattern (n = 22, 52.4%). Notably, features considered significant for atypical melanocytic nevi included 9 nevi with scant atypical melanocytes (21.4%) and 3 nevi with nonedge papillae (7.1%). None of the studied lesions required biopsy among this cohort.

CONCLUSIONS

Most rapidly growing and clinically changing nevi rarely exhibit single atypical cells in the DEJ. The RCM served as a valuable adjunct to dermoscopy, allowing reassurance in the evaluation of these lesions.

Unexpected postoperative atlantoaxial rotatory subluxation after excision of melanocytic nevi of the head and neck in older children: two case reports and literature review

Postoperative atlantoaxial rotatory subluxation (AARS) is a rare complication that develops almost exclusively in children following oropharyngeal and otologic surgeries, proposing that oropharyngeal inflammatory responses and excessive head rotation are responsible factors. However, there have been no reports of AARS after excision of a nevus on the head and neck. Here, we present two cases of AARS following limited head rotation during simple nevus excision. Patient 1, a 9-year-old girl, complained of neck pain and limited range of motion after excision of the nevus on the neck. After 2 months, computed tomography and magnetic resonance imaging finally revealed AARS with a ruptured transverse atlantal ligament. A month of halo traction was required for the treatment. Patient 2, an 11-year-old girl, presented with immediate pain and limited neck extension after tissue expander insertion under the upper chest and excision of the nevus on her left cheek. The diagnosis was promptly made using cervical spine radiography. A cervical collar was applied for 1 month. Both patients recovered without any complications after treatment. This report highlights the importance of suspicion for AARS after surgery regardless of surgical duration or amount of head rotation.

Paediatric Spitzoid Neoplasms: 10-Year Retrospective Study Characterizing Histological, Clinical, Dermoscopic Presentation and FISH Test Results

INTRODUCTION

Spitzoid lesions are a wide tumour class comprising Spitz nevus (SN), atypical Spitz tumour (AST) and Spitz melanoma (SM).

MATERIALS AND METHODS

We conducted a single-centre-based retrospective survey on all histologically diagnosed spitzoid lesions of paediatric patients (1-18 years) of the last 10 years (2012-2022). Histopathological reports and electronic records of patients were used to retrieve relevant data regarding patients' features, clinical and dermatoscopical aspects of lesions when recorded, and FISH tests when present.

RESULTS

Of 255 lesions, 82% were histologically benign, 17% atypical, 1% malignant. Clinically, 100% of SM were large (≥6 mm) and raised; AST were mainly large (63%), raised (98%), pink (95%). Small (≤5 mm), pigmented, flat lesions correlated with benign histology (respectively 90%, 97%, 98% SN) (p < 0.0001). Dermatoscopical patterns were analysed in 100 patients: starburst pattern correlated with benign histology (26% SN (p = 0.004)), while multicomponent pattern correlated with atypical/malignant lesions (56% AST, 50% SM (p = 0.0052)). Eighty-five lesions were subjected to fluorescence in situ hybridization (FISH): 34 (71% AST; 29% SN) were FISH-positive; 51 (63% SN; 37% AST) were FISH-negative (p = 0.0038).

DISCUSSION

This study confirmed predominant benign histology (82%) of paediatric spitzoid lesions, thus detecting 17% AST and 1% SM, highlighting the need for caution in handling spitzoid lesions.

CONCLUSION

Until AST are considered potentially malignant proliferations and no reliable criteria are identified to distinguish them, the authors suggest a prudent approach, especially in children.

Surgical management of facial congenital melanocytic nevi: Experiences and outcomes at an academic center

BACKGROUND

Congenital melanocytic nevi (CMN), benign pigmented birthmarks caused by the mutation of melanocytic cells during embryofetal development, can cause aesthetic problem when it is located on the face. Surgical managements of facial CMN are required by both pediatric patients and their parents. Surgical management, including excision or staged excision, skin grafting, dermabrasion, tissue expansion or multiple re-expansion combined with flaps transplantation, have been reported previously. However, a systematical report about facial CMN management is still scarce.

OBJECTIVE

Herein, we have reviewed our serious of patients with facial CMN, noting their size, location, and histological examination, summarizing the surgical relation behind reconstructive and cosmetic treatment, and proposing a newly classification for facial CMN among pediatric patients, hoping to share a useful surgical algorithm for these lesions on this specific part.

CONCLUSION

Proper surgical strategy should be made based on the size and location of the nevi and the adjacent relationship between the location and relaxed skin tension lines and aesthetic units. Postoperative ant-scar treatment improves aesthetic outcomes. With our experience and surgical algorithm about facial CMN surgery, a favorable outcome can be achieved.

Genodermatoses associated with melanocytic nevi

Though melanocytic nevi are ubiquitous in the general population, they can also be key cutaneous manifestations of genetic syndromes. We describe genodermatoses associated with melanocytic nevi and discuss their clinical characteristics, cutaneous manifestations, underlying genetics, and, if applicable, guidelines for when genetic testing should be performed. We categorized these genodermatoses based on their association with congenital nevi, acquired nevi, or nevi whose first appearance is unknown. In many cases, the distinctive morphology or distribution of melanocytic nevi can be an important clue that an underlying genetic syndrome is present, allowing both the patient as well as family members to be screened for the more serious complications of their genetic disorder and receive education on potential preventative measures. As we continue to advance our understanding of how various genotypes give rise to the wide spectrum of phenotypes observed in these genodermatoses, we shall be able to better stratify risk and tailor our screening methods to clinically manage the heterogeneous manifestations of genodermatoses among these patients.

Review article: Emerging issues in pediatric skin of color, Part 2

Dermatology for pediatric skin of color is the application of dermatology to the genetically diverse and distinctive segment of the pediatric population that includes children of non-White racial and ethnic groups with increased pigmentation including individuals of Asian, Hispanic/LatinX, African, Native American, Pacific Island descent, indigenous people among others with overlap in particular individuals, and mixtures thereof. The discipline of pediatric skin of color can be challenging with difficulty in diagnosis of common conditions due to underlying pigmentation, variations in common hair styling practices, and differences in demographics of cutaneous disease. Whereas some conditions are more common in children of color, other conditions have nuances in clinical appearance and therapeutics with regard to skin color. This article, the second of the series, focuses on inflammatory skin disease nuances, melanocytic disorders, and hypopigmented mycosis fungoides.

Spitz Nevus: Review and Update

The Spitz nevus is an uncommon melanocytic nevus. These lesions classically appear in childhood as a red, dome-shaped papule. They appear rarely in adults and may be pigmented. The Spitz nevus can develop suddenly and grow rapidly, reaching a 1-cm diameter in 6 months or less. There are 3 classes of spitzoid neoplasms: typical Spitz nevus, atypical Spitz nevus, and spitzoid melanoma. The diagnosis should be cautiously differentiated, especially in children. Immunohistochemistry and molecular studies have been helpful in differentiating difficult cases; however, no set of criteria has been accepted to predict biological behavior of atypical Spitz nevi.

Demographic, clinical and dermoscopic features of melanocytic nevi on the scalp

BACKGROUND

The scalp is a special anatomical area and dermoscopic findings of this region may significantly differ from other body parts.

OBJECTIVE

To investigate and compare the clinical and dermoscopic patterns of scalp melanocytic nevi in patients ≤15 years of age and above, and to analyse their relevance to demographic features, atypical mole syndrome (AMS) and total body nevus count (TBNC).

METHODS

In this retrospective cohort study, the clinical data and dermoscopic images of patients with scalp melanocytic nevi were retrieved, reviewed and analysed. Demographic, clinical and dermoscopic features were compared in patients ≤15 years of age and above.

RESULTS

A total of 196 scalp melanocytic nevi in 126 patients (female/male:64/62; ≤15/>15 years of age: 49/77) with a median age of 18.5 years (range 0-72) were evaluated. Statistically, the globular pattern was significantly higher in all age groups, and the papillomatous pattern was significantly lower in patients ≤15 years of age (P = 0.008 and P = 0.005, respectively). The eclipse pattern was significantly higher, and the homogenous pattern was significantly lower in patients ≤15 years of age with AMS (P = 0.003 and P = 0.014, respectively). Finally, patients ≤15 years of age with 50 to 100 TBNC had a higher eclipse pattern than those with 0 to 25 TBNC.

CONCLUSION

The findings of this retrospective study might implicate that children with eclipse pattern of scalp melanocytic nevi might be 'moley' in the future with an impending risk of AMS. This hypothesis requires confirmation in future prospective studies on a larger cohort of patients.

18F-FDG PET/CT Imaging in an Unusual Case of Cutaneous Melanoma Arising From Congenital Melanocytic Nevus in a Two-year-old Girl

Childhood malignant melanoma (MM) is extremely uncommon. We report an unusual case of cutaneous melanoma that developed from a medium-sized congenital melanocytic nevus (CMN) in a two-year-old girl. The patient had a history of CMN on the right hip, and she presented with a new ulcerative area with irregular borders and bleeding on CMN. Histopathological examination of the nevus revealed a MM. ¹⁸Florfluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography was performed for metastatic evaluation. The scan demonstrated metastatic increased ¹⁸F-FDG uptake in the right external iliac and inguinal lymph nodes.

A sixteen-year single-center retrospective chart review of Spitz nevi and spitzoid neoplasms in pediatric patients

BACKGROUND

Spitzoid neoplasms in pediatric patients pose an interesting challenge for clinicians. More data on the clinical, histologic, and molecular characteristics of these lesions are necessary to distinguish features that may portend recurrence or malignant behavior to help determine future treatment guidelines in pediatric patients.

METHODS

Institutional Review Board approval was obtained from Children's Hospital of Wisconsin to conduct a retrospective analysis of spitzoid neoplasms. Patients with biopsied or excised spitzoid neoplasms between 01/01/2000 and 08/01/2016 were included. Pertinent clinical and histologic data were collected. Atypical, unusual, or diagnostically uncertain lesions were selected for re-review.

RESULTS

266 lesions from 264 patients were included. 243 were classified as benign (91.35%), 22 as atypical (8.27%), and 1 as spitzoid melanoma (0.38%). No clinical or histologic variables were found to be statistically significant between the benign Spitz, atypical Spitz, and spitzoid melanoma cohorts. No known deaths occurred.

CONCLUSION

Our findings highlight the extreme variability of spitzoid neoplasms clinically and histologically. Importantly, this study demonstrates that the vast majority of spitzoid neoplasms in pediatric populations are benign and supports conservative management of spitzoid lesions in children.

Surgical treatment of children and youth with congenital melanocytic nevi: self- and proxy-reported opinions

PURPOSE

The role of surgery in the management of congenital melanocytic nevi (CMN) is controversial. Data on surgical outcomes and predictors of satisfaction remain scarce.

METHODS

An online survey was employed following worldwide recruitment of youth aged 14-25 years (n = 44) and parents of children ≤ 18 years (n = 249) with CMN to query patterns of treatment and satisfaction with and opinions about the benefits of surgery.

RESULTS

In proxy-reports, 121 of 249 (49%) and in self-reports 30 of 44 (75%) participants underwent CMN excision. The most common reasons for surgery were psychosocial determinants, aesthetic improvement, and melanoma risk reduction. The overall satisfaction with surgical management was good, although no predictors for satisfaction could be identified. Higher current age of the child was found to predict decision regret in proxy-reports. Most participants indicated that having a scar is more socially acceptable than a CMN. Opinions differed on whether surgery should be deferred until the child is old enough to be involved in the decision-making process.

CONCLUSIONS

Whether and when to perform surgery in children with CMN is a multifaceted question. Awareness of common concerns as well as risks and benefits of surgery are essential to ensure critical reflection and balanced decision-making.

Increased melanocytic nevi and lentigines in two patients with harlequin ichthyosis

An increased number of melanocytic nevi and lentigines have been reported in patients with two types of autosomal recessive congenital ichthyosis (ARCI): lamellar ichthyosis and nonbullous congenital ichthyosiform erythroderma. These melanocytic lesions may have clinical and dermoscopic features of atypia, necessitating close surveillance. Here, we report two interesting cases of pediatric patients with harlequin ichthyosis (HI) who developed increased melanocytic nevi and lentigines. These cases are unique in that the patients presented at a younger age and one patient had a darker skin phototype than previously described in the literature.

Management of congenital melanocytic nevi in the plastic surgery clinic: Families' expectations and their persistent concern about malignancy

BACKGROUND

Children with congenital melanocytic nevi (CMN) were historically managed with surgical removal to lower the risk of malignant transformation. The evolving literature over the last decade has indicated a significantly lower risk than previously estimated. Indications for excision currently revolve around aesthetic and psychosocial concerns. This study describes and evaluates the perspectives and expectations of patients and families referred to a pediatric plastic surgery clinic on CMN management.

METHOD

A two-part questionnaire was administered before and after an initial clinic appointment to evaluate patient and family concerns of lesion growth, risk of malignancy, treatment expectations, and stigmatization.

RESULTS

Thirty questionnaires were completed for 11 male and 19 female patients, mean age 9.2 years (1-25). Referring doctors (majority dermatologists) were rarely concerned about malignancy (8%), but parents listed it as a top reason for wanting the CMN removed (37%) and the most common expectation for the visit followed by information about surgical options and outcome. Before the clinic, 93% were at least "slightly" worried about CMN growth and 96% about malignancy, whereas 63% and 72%, respectively, after the clinic.

CONCLUSIONS

Families want information about surgical excision and are concerned about malignancy, indicating lingering misinformation or misconception about melanoma risk. For the majority, CMN removal remains at least slightly important, presumably for aesthetic reasons and remaining concern about malignancy. Involved health care professionals should assure reliable and coherent patient information about MM risk, indications for surgery and expected outcome to best support families' decision-making.

Pathology of Melanoma

Melanoma is an aggressive malignancy arising from melanocytes in the skin and rarely in extracutaneous sites. The understanding of pathology of melanoma has evolved over the years, with the initial classifications based on the clinical and microscopic features to the current use of immunohistochemistry and genetic sequencing. The depth of invasion and lymph node metastasis are still the most important prognostic features of melanoma. Other important prognostic features include ulceration, lymphovascular invasion, mitosis, and tumor-infiltrating lymphocytes. This article reviews the pathology of melanoma and its precursor lesions, along with the recent advances in pathologic diagnosis of melanoma.

Juvenile melanocytic acral nevus: A comparative study between MANIAC and non-MANIAC nevus and its clinicopathological characteristics

BACKGROUND

Melanocytic acral nevi have a series of distinguishing features, including their location, patient age at onset, clinical progression, and histological findings. In particular, histopathological analysis often reveals a melanocytic acral nevus with intraepidermal ascent of cells (MANIAC nevus), which in some cases can be mistaken for atypia or malignancy.

AIM

This study describes the clinicopathological characteristics of acral nevi in patients under 18 years old and contrasts the clinical and histological features between MANIAC vs non-MANIAC nevi.

METHODS

This was a retrospective observational study, performed in our department in the decade between January 2007 and January 2017. We included patients younger than 18 years of age who were subjected to the removal of melanocytic acral nevi.

RESULTS

A total of 70 patients were studied. 54.2% (38/70) were females and 45.8% (32/70) were males. With regard to the type of nevus, 34 were compound, 27 were junctional, and 9 were predominantly intradermal lesions. We identified a total of 41 MANIAC nevi and 29 non-MANIAC nevi. Statistically significant differences between these two groups were identified in nevus size (larger in MANIAC) and the frequency of compound nevi (higher in the MANIAC group), but not in the remainder of the histological parameters studied.

Giant Congenital Melanocytic Nevus Treated With Trametinib

Giant congenital nevi are melanocytic proliferations of the skin that may be complicated by melanoma, neurocutaneous melanocytosis, pain, pruritus, and disfigurement. Current treatment options include surgical resection and medical management of associated symptoms. There is limited efficacy in these modalities. No effective pharmacologic treatments are available for the treatment of these lesions. We present the case of a 7-year-old girl with a giant congenital melanocytic nevus that had an AKAP9-BRAF fusion and was treated with trametinib, which resulted in rapid resolution of the patient's lifelong, intractable pain and pruritus as well as dramatic improvement in the extent of her nevus.

Evolution of congenital melanocytic nevi toward benignity: A case series

We report on four children born with medium to large congenital melanocytic nevi (CMN) with color heterogeneity and irregular surface rugosity. As these patients aged, their nevi evolved to become more homogeneous and lighter in color, and developed a smoother, more even texture. We propose that given this evolution toward benignity, conservative monitoring and management may be appropriate even in the context of atypical-appearing features at birth. Such knowledge regarding the evolution of these CMN can more accurately guide parents and clinicians in determining whether to biopsy or remove an atypical-looking lesion early in life for medical or cosmetic reasons.

Acral pigmented Spitz nevus in a child with transepidermal migration of melanocytes: Dermoscopic and reflectance confocal microscopic features

Acral pigmented Spitz nevi are seldom reported in the literature. We report a new case on the palm of a 4-year-old girl that demonstrated correlation between features observed on dermoscopy and reflectance confocal microscopy (RCM). Histopathology revealed a benign intraepidermal Spitz nevus with transepidermal elimination of melanocytes that showed on RCM as focal atypical bright cells concerning for malignancy. This case is one of few reports in the literature combining dermoscopy, reflectance confocal microscopy, and histology for an acral Spitz nevi, which are rarely evaluated by RCM given the thickness of the stratum corneum in acral sites.

Common and not so Common Melanocytic Lesions in Children and Adolescents

The acquired melanocytic nevus is the most common lesion encountered by pediatric pathologists and dermatopathologists in their daily practice. In most cases, there are few difficulties in histopathologic diagnosis. However, it is the acquired melanocytic lesion known as the Spitz nevus, with its intrinsic atypical features which becomes the challenge since it exists along a histopathologic and biologic continuum from the atypical Spitz tumor to spitzoid melanoma. The frustration with some of these spitzoid lesions is that even the "experts" cannot agree as to the differentiation of one from the other even at the level of molecular genetics. Other melanocytic lesions are discussed including the congenital melanocytic nevus with its proliferative nodule(s) and melanoma as the ultimate complication. Although uncommon, cutaneous melanoma in the first 2 decades is emerging as a clinical problem especially in young women in the second decade of life. These are ultraviolet-associated neoplasms whose histopathologic and prognostic features are identical to the adult experience. Considerable progress has been made over the past 15 to 20 years in our understanding of cutaneous melanocytic lesions, but gaps still exist in the important group of spitzoid lesions. It can also be anticipated that more cutaneous melanomas in children will be seen in the future based upon epidemiologic studies.

Melanocytic nevi and melanoma: unraveling a complex relationship

Approximately 33% of melanomas are derived directly from benign, melanocytic nevi. Despite this, the vast majority of melanocytic nevi, which typically form as a result of BRAF^V600E-activating mutations, will never progress to melanoma. Herein, we synthesize basic scientific insights and data from mouse models with common observations from clinical practice to comprehensively review melanocytic nevus biology. In particular, we focus on the mechanisms by which growth arrest is established after BRAF^V600E mutation. Means by which growth arrest can be overcome and how melanocytic nevi relate to melanoma are also considered. Finally, we present a new conceptual paradigm for understanding the growth arrest of melanocytic nevi in vivo termed stable clonal expansion. This review builds upon the canonical hypothesis of oncogene-induced senescence in growth arrest and tumor suppression in melanocytic nevi and melanoma.

Paediatric melanoma

Paediatric melanoma, although rare, is the most common skin cancer in children. Our current knowledge on paediatric melanoma incidence trends is expanding, as several studies have addressed this issue with conflicting results. Known risk factors for paediatric melanoma include family history of melanoma, a previous history of malignancy, large congenital nevi, numerous melanocytic nevi, sunburns, increased UV exposure and a sun-sensitive phenotype. In younger children, melanoma more often presents with atypical features, such as a changing, amelanotic or uniformly coloured, often bleeding lesion, not fulfilling in most cases the conventional ABCDE criteria. The major differential diagnoses are melanocytic nevi, proliferative nodules in congenital nevi and atypical Spitz tumours. Moreover, in the younger age group non-Caucasian children are over-represented, tumours tend to be thicker and lymph nodes are often involved. Despite the frequent diagnosis at an advanced stage, the overall survival is fair in paediatric melanoma. Specific guidelines for management of melanoma in children do not exist, and most often the disease is treated similarly to melanoma in adults.

Congenital melanocytic nevi in young children: Histopathologic features and clinical outcomes

BACKGROUND

Although only large congenital melanocytic nevi (CMN) are associated with a significantly high risk for malignant transformation, CMN of all sizes are prone to changes in clinical appearance in early childhood and thus are often biopsied or excised. While CMNs typically exhibit benign behavior, atypical histopathologic findings might be common and may prompt additional unnecessary procedures.

OBJECTIVE

To assess the prevalence and associated clinical outcomes of atypical histopathologic features in CMN in children.

METHODS

A single center retrospective study was conducted with patients 0-35 months of age with CMN diagnosed by histopathology between 1993-2013.

RESULTS

One hundred seventy-nine patients with a total of 197 CMNs were identified. Cytologic atypia, architectural disorder, or pagetoid spread were present in 73% of CMN. With a mean follow up of 7.3 years, no cases of melanoma or CMN-related deaths were identified.

LIMITATIONS

Our findings were based on a largely Caucasian population and might not apply to darker skin types. Our findings might not apply to older children or adults with CMN.

CONCLUSION

Atypical histopathologic features of cytologic atypia, architectural disorder, and pagetoid spread are common in benign CMN of young children.

Spitz Nevi and Other Spitzoid Neoplasms in Children: Overview of Incidence Data and Diagnostic Criteria

Spitz nevi are benign melanocytic neoplasms characterized by epithelioid or spindle melanocytes or both. In some rare cases their presentation overlaps with the clinical and histopathologic features of malignant melanoma, so a differential diagnosis can be difficult to make. Intermediate forms between Spitz nevi and malignant melanoma, with unpredictable behavior, have been called atypical Spitz tumors. A literature search was performed to review the clinical, dermoscopic, genetic, and histopathologic aspects of spitzoid tumors. Spitz nevi mainly occur in children, with no predilection for sex, and in young women. Common sites are the head and lower arms, where Spitz nevi present as pink nodules or hyperpigmented plaques. Spitzoid lesions may have diverse dermoscopic patterns: vascular, starburst, globular, atypical, reticular, negative homogeneous, or targetoid. The management of spitzoid lesions can be invasive or conservative; surgical excision is usually reserved for those with doubtful features, whereas clinical and dermoscopic follow-up is preferred for typical pediatric Spitz nevi. The role of sentinel lymph node biopsy in atypical Spitz tumors is debated. Immunohistochemistry and new molecular techniques such as comparative genomic hybridization, polymerase chain reaction, and fluorescence in situ hybridization offer new diagnostic perspectives, investigating genetic alterations that are specific for malignant melanoma or for Spitz nevi.

Congenital melanocytic nevi: update in genetics and management

PURPOSE OF REVIEW

The article intends to review recent updates in the management of congenital melanocytic nevi (CMN) and the evolving genomic landscape that has begun to shed light on the nature of nevogenesis, malignant potential, and possible therapeutic targets for those with melanoma and neurologic involvement.

RECENT FINDINGS

CMN are the result of postzygotic somatic mutations involving key proteins in the mitogen-activated protein kinase pathway, primarily NRAS and BRAF. Complications include a spectrum of neurologic findings and development of melanoma. Patients with extracutaneous involvement may be better termed as having 'CMN syndrome'. MRI findings in high risk patients with multiple CMN may best predict clinical outcome.

SUMMARY

The management of patients with CMN is complex. Neurologic involvement and melanoma remain the two most devastating complications. New, genetically targeted therapies for patients with complications may be of value, and research for potential therapies is ongoing.

Melanocytic Nevi in Children: A Review

Common moles on the skin, known scientifically as melanocytic nevi, are seen frequently in the pediatric population. They are broadly grouped into two groups: congenital (generally present at birth or in infancy) or acquired. Congenital melanocytic nevi (CMN) are classified based on size and morphologic features. Neurocutaneous melanosis and melanoma represent two important complications, with overall risk affected by nevus size, location, appearance, and number of satellite lesions. Regular lifelong skin surveillance is required for high-risk CMN. Acquired melanocytic nevi (AMN) tend to appear in childhood and increase in number through adolescence. Risk factors for melanoma in children with moles include having more than 50 AMN, clinically atypical AMN, family history of melanoma, excessive ultraviolet light exposure, lightly pigmented skin, and immunosuppression. Children with risk factors should be monitored regularly. The periodic health examination presents an opportunity to perform total body skin examination to screen for concerning lesions and to provide anticipatory guidance about sun protection. [Pediatr Ann. 2016;45(8):e293-e298.].