Update on dermoscopy of Spitz/Reed naevi and management guidelines by the International Dermoscopy Society

Dermoscopic structures and patterns used in melanoma detection

Melanoma is the leading cause of skin cancer-related deaths. Yet, early detection remains the most cost-effective means of preventing death from melanoma. Early detection can be achieved by a physician and/or the patient (also known as a self-skin exam). Skin exams performed by physicians are further enhanced using dermoscopy. Dermoscopy is a non-invasive technique that allows for the visualization of subsurface structures that are otherwise not visible to the naked eye. Evidence demonstrates that dermoscopy improves the diagnostic accuracy for skin cancer, including melanoma; it decreases the number of unnecessary skin biopsies of benign lesions and improves the benign-to-malignant biopsy ratio. Yet, these improvements are contingent on acquiring dermoscopy training. Dermoscopy is used by clinicians who evaluate skin lesions and perform skin cancer screenings. In general, under dermoscopy nevi tend to appear as organized lesions, with one or two structures and colors, and no melanoma-specific structures. In contrast, melanomas tend to manifest a disorganized pattern, with more than two colors and, usually, at least one melanoma-specific structure. This review is intended to familiarize the reader with the dermoscopic structures and patterns used in melanoma detection.

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.

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.

Clinical, Dermoscopic, and Histological Characteristics of Melanoma Patients According to the Age Groups: A Retrospective Observational Study

BACKGROUND

Although the role of melanoma risk factors is well documented, their correlation with patients' age is less frequently analyzed.

METHOD

The analysis was performed among 189 melanoma patients in different age groups, including <30 years, 31-60 years, and >60 years, to investigate the risk factors, topography, and coexistence of morphological features of 209 melanomas (dermoscopic and histopathological).

RESULTS

Among the youngest age group, no correlation with the presence of estimated risk factors was found. The most common dermoscopic pattern was spitzoid and multicomponent asymmetric. The group of middle-aged patients was the most diverse in terms of the occurrence of risk factors, solar lentiginosis, dermoscopic patterns, topography, histological subtypes, and invasiveness of melanomas. The oldest group characterized a strong correlation between solar lentiginosis, NMSC comorbidity, the prevalence of facial melanomas, the dermoscopic pattern of melanoma arising on chronic sun-damaged skin, and regression.

CONCLUSION

The findings regarding the presence of age-specific features in melanoma patients, especially in the youngest and middle-aged groups, might be helpful for clinicians and to target secondary prevention efforts.

Rapid growth and slow involution of Reed nevus in a long-term dermoscopic follow-up

We describe the rapid growth of a Reed nevus followed by its slow involution and present dermoscopic follow-up images. The child was monitored for 10 years (from age 3 to 13 years) by digital dermoscopy. The Reed nevus completely lost its typical dermoscopic arrangement (starburst pattern) with involution and distinct changes in dermoscopic pattern.

The Spectrum of Spitz Melanocytic Lesions: From Morphologic Diagnosis to Molecular Classification

Spitz tumors represent a distinct subtype of melanocytic lesions with characteristic histopathologic features, some of which are overlapping with melanoma. More common in the pediatric and younger population, they can be clinically suspected by recognizing specific patterns on dermatoscopic examination, and several subtypes have been described. We now classify these lesions into benign Spitz nevi, intermediate lesions identified as “atypical Spitz tumors” (or Spitz melanocytoma) and malignant Spitz melanoma. More recently a large body of work has uncovered the molecular underpinning of Spitz tumors, including mutations in the HRAS gene and several gene fusions involving several protein kinases. Here we present an overarching view of our current knowledge and understanding of Spitz tumors, detailing clinical, histopathological and molecular features characteristic of these lesions.

"Red Spitz Tumor" on the Ear: Case Report and Review of the Literature

Spitz nevus (SN) is a benign melanocytic lesion with cytologic and architectural atypia. It is sometimes difficult to distinguish SNs from atypical Spitz tumor (AST), Spitz melanoma, or conventional melanoma. SNs frequently develop in Caucasians and appear on the skin of the head and lower extremities. Lesions on the ear in Asian populations are rare. Here, we report a “red Spitz tumor” on the ear of a Chinese 18-year-old boy. Dermoscopic examination revealed possibly malignant features presented as polymorphous vessels along with central white area, pseudo-network depigmentation and atypical peripheral globular pattern. The results of histopathological examination strongly suggested that the neoplasm was a compound SN and no recurrences or metastases occurred during 1-year follow-up post-surgery. Further, we review the literature on 4 previously reported cases of SN on the ear and summarize the main points of SN diagnosis and differential diagnosis with atypical Spitz tumors and melanoma.

Dermoscopy of Small Diameter Melanomas with the Diagnostic Feasibility of Selected Algorithms-A Clinical Retrospective Multicenter Study

Simple Summary

The early detection of melanoma determines the recovery of the patient. Dermoscopy, which is one of the diagnostic tools for pigmented lesions, is characterized by high sensitivity and specificity, giving the clinician the possibility to detect the presence of abnormal structures before their clinical presentation. There are a small number of dermoscopic analyses of pigmented lesions of less than 6 mm in diameter in the published literature. The authors attempted to identify characteristic dermoscopic structures typical for melanomas of less than 5 mm in diameter in comparison with a group of melanomas exceeding this dimension at an identical clinical stage. It was found that dermoscopy in the secondary prevention of micromelanomas (appearing mainly as brown lesions) revealed the presence of dotted or polymorphous vessels, with architectural disorder in half of cases. Moreover, spitzoid, multicomponent asymmetric or nonmelanoma-specific patterns prevailed. Knowledge of these dermoscopic features brings the clinician closer to an early diagnosis of melanoma with a diameter of 5 mm or less.

Abstract

Objective: The aim of the study was to verify two hypotheses. The first concerned the possibility of diagnostic dermoscopic differentiation between cutaneous melanomas of the histopathological category in situ (pTis) and thin melanomas (pT1a) in terms of their diameter. The second assessed the diagnostic feasibility of two dermoscopic algorithms aiming to detect ≤ 5.0 mm-sized melanomas histopathologically confirmed as pTis and pT1a. Methods: Dermoscopic images of consecutive cases of histopathologically confirmed melanomas were evaluated by three independent investigators for the presence of the predefined criteria. The melanomas were subdivided according to their diameter into small melanomas, so-called micromelanomas (microM)—sized ≤ 5.0 mm and >5.0 mm, according to published definitions of small melanocytic lesions. The Triage Amalgamated Dermoscopic Algorithm (TADA) and the revisited 7-point checklist of dermoscopy (7-point) algorithm were chosen for the diagnostic feasibility. Odds ratios and corresponding 95% confidence limits (CL) were calculated using the logistic regression adjusted for age for the melanoma-specific dermoscopic structures, the dermoscopic patterns and the diagnostic feasibility of the 7-point checklist and TADA algorithms. The p-values of the results were corrected using the Bonferroni method. Results: In total, 106 patients with 109 melanomas, 50 sized ≤ 5.0 mm and 59 exceeding the diameter of 5.0 mm, were retrospectively analyzed. The prevalent general pattern of microM was the spitzoid one (48% vs. 11.86%, p = 0.0013). Furthermore, 40% of microM vs. 6.78% melanomas sized > 5.0 mm (p = 0.0023) did not present melanoma-specific patterns. The asymmetric multicomponent pattern was present in 64.41% melanomas sized > 5.0 mm and in 26.00% microM (p = 0.0034). The asymmetry of structures or colors was detected in 56% microM vs. 89.83% (p = 0.0020) and 56% microM and 94.92% (p = 0.000034) melanoma sized > 5.0 mm, respectively. The differences in frequency of the detected dermoscopic structures specific to melanomas revealed that microM are almost deprived of negative networks (p = 0.04), shiny white structures (p = 0.0027) and regression features (p = 0.00003). Neither prominent skin markings nor angulated lines were found in the entire study group. Out of the vascular structures, microM presented only dotted (32%) or polymorphous (28%) vessels, although more rarely than melanomas sized > 5.0 mm (66.1% p = 0.017 and 49% p > 0.05, respectively). The diagnostic feasibility revealed a score ≥ 3 of the 7-point algorithm (indicative for malignancy) in 60% microM and 98.31% melanomas sized > 5.0 mm (p = 0.000006). The TADA algorithm revealed melanoma-specific patterns in 64% microM and 96.61% > 5.0 mm-sized melanomas (p = 0.00006) and melanoma-specific structures in 72% and 91.53% (p > 0.05), respectively. Conclusion: In the dermoscopy, 40% of micromelanomas histopathologically staged as pTis and pT1a did not reveal melanoma-specific patterns. Among the general melanocytic patterns, the spitzoid one was the most frequently found in melanomas sized ≤ 5.0 mm. The 7-point checklist and TADA dermoscopic algorithms were helpful in the identification of the majority of melanomas sized ≤ 5.0 mm.

Pigmented Lesions in Children: Update on Clinical, Histopathologic and Ancillary Testing

Patients are commonly referred to pediatric dermatology for the evaluation of pigmented lesions. For families, pediatricians, and dermatologists alike, malignancy is the main fear. In the past few decades, there has been evolving literature to inform diagnosis and management. This article provides an update on the clinical, histopathologic, and ancillary testing for 3 categories of particularly challenging pigmented lesions: congenital melanocytic nevi, spitzoid neoplasms, and pediatric melanoma.

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.

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.

Usefulness of Dermoscopy to Provide Accurate Assessment of Skin Cancers

Seborrheic keratosis (SK) is the most common benign tumour of epidermal origin. In most cases, it is simple to recognize in the clinical examination. However, sometimes SK can be a problematic lesion. We present the cases of two patients with seborrheic keratosis in whom we diagnosed the skin cancer through dermoscopic and histopathological examinations. The article aims to draw attention to the need for dermoscopic examinations to be included for an accurate assessment of the nevi not only by dermatologists but also not-specialized doctors. We would like to underline that many skin cancers share the similar features of malignancy, and competence and capability to interpret the dermoscopic pictures correctly are important for early recognition of malignant lesion. Very often malignant skin cancers can be hidden among benign lesions like seborrheic keratosis or they can be imitators of benign lesions. Amongst all cases of imposing SK, basal cell carcinoma, squamous cell carcinoma, melanoma is the most important differential diagnosis, of which their dermoscopic features will be discussed in this article.

Dermoscopic Features Summarization and Comparison of Four Types of Cutaneous Vascular Anomalies

Objective: Dermoscopic features of cutaneous vascular anomalies have been reported, but the described features currently known are limited and not well-understood. The aim of this study is to comprehensively summarize and compare the dermoscopic features of the four different types of cutaneous vascular anomalies [infantile hemangiomas (IH), cherry angioma (CA), angiokeratomas (AK), and pyogenic granuloma (PG)] in the Chinese Han population.

Materials and Methods: Dermoscopic features of 31 IH, 172 CA, 31 AK, and 45 PG were collected based on the contact non-polarized mode of dermoscopy at 20-fold magnification. Dermoscopic features including background, lacunae, vessel morphology and distribution were collected and summarized. Additionally, we compared these features by age stage, gender, and anatomical locations in CA.

Results: The dermoscopic features of IH included the red lacunae, red/red-blue/red-white backgrounds, and vessel morphology such as linear curved vessels, serpiginous vessels, coiled vessels. For CA, the lacunae appeared reddish brown to reddish blue or only red. In terms of vascular morphology, serpentine vessels, coiled vessels, looped vessels, and curved vessels could be seen in the lesions. A few lesions were black or presented with a superficial white veil. There were statistical differences in red background (P = 0.021), unspecific vessel distribution (P = 0.030), black area (P = 0.029), and white surface (P = 0.042) among different age groups. Red-brown lacunae (P = 0.039), red-blue (P = 0.013), red-white background (P = 0.015), black area (P = 0.016), and white surface (P = 0.046) were of statistical difference in terms of the locations of lesions. Lacunae were also observed in AK, which presented with red, dark purple, dark blue, black. Global dermoscopic patterns that were characterized by a homogeneous area were obvious in all PG lesions, among which 30 (66.7%) were red-white and 15 (33.3%) were red. As for local features, “white rail” lines were detected in 19 (42.2%) lesions and white collarette was seen in 34 (75.6%) lesions.

Conclusions: Dermoscopy is an applicable diagnostic tool for the diagnosis of cutaneous vascular anomalies. It is necessary to take into account the age stage and lesion location when we diagnose CA using dermoscopy.

Clinical and dermoscopic polymorphisms in agminated Spitz nevi: Ugly presentation but benign behavior

Agminated Spitz nevi are an uncommon entity, and their management is challenging due not only the young age of the patients but also the tumor's uncertain malignant potential and the variability in the dermoscopic and clinical presentation. We report a case of a 6-year-old boy with multiple agminated Spitz nevi on a café au lait macule with different atypical clinical patterns and dermoscopic features.

[Noninvasive diagnostic imaging in pediatric skin lesions]

Optical coherence tomography (OCT) and reflectance confocal laser microscopy (RCM) allow noninvasive imaging diagnostics of the skin. Since the indication for a biopsy in children is generally made cautiously, OCT and KLM can be helpful in the clarification of pediatric skin lesions. In addition, biopsies only represent a snapshot of a small area of the skin, while noninvasive methods allow several locations to be examined over time, so that dynamic changes and the course of therapy can also be determined. In pediatric dermatology, these diagnostic methods are particularly suitable for the clarification of atypical pigment lesions, for infectious dermatoses such as scabies or tinea, and for the diagnosis of inflammatory and degenerative dermatoses.

Management of Residual Spitz Nevus in Surgical Specimens following Biopsy and Excision

Proper management of Spitz nevi continues to be debated, with treatment ranging from observation to surgery. To better characterize the outcome of surgical procedures performed for incomplete initial excision or biopsy, we sought to ascertain the histopathological presence of residual Spitz nevi in a set of surgical specimens.

Methods

We retrospectively reviewed 123 records with histologically-confirmed Spitz nevus. Data concerning treatment, clinical features, histopathological margin involvement, and presence of residual lesion on subsequent procedural specimens were collected.

Results

Fifty-three percent of lesions (n = 65) were initially sampled by shave or punch biopsy, and the remainder (n = 58) were formally excised without initial biopsy. The rates of re-excision for involved margins were: shave biopsy (92.2%), punch biopsy (78.6%), and formal excision (13.8%). In total, 61.0% of patients who underwent an initial procedure of any kind had involved margins, but only half of those re-excised for involved margins (57.6%) had histologically residual lesion on repeated excision. A significantly higher proportion of initial punch biopsies (90.9%) resulted in residual lesion (in secondary excision specimens) when compared with shave biopsy (48.9%) and formal excision (62.5%; P < 0.05).

Conclusions

Findings suggest that clinicians may consider shave biopsy over punch biopsy for diagnosing suspected lesions, when indicated and appropriate. Given the rarity of malignant transformation and the frequency of residual nevus, observation may be reasonable for managing pediatric patients with histologically-confirmed Spitz nevi, who are post initial biopsy or excision despite known histopathological margin involvement.

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.

Metastatic PRAME-Expressing Juvenile Spitzoid Melanoma on the Buttock

Since the cost of molecular biological methods for Spitzoid neoplasms is expensive, the number of institutes that employ these methods might be limited. Preferentially expressed antigen in melanoma (PRAME) is a tumor-associated antigen that is useful to distinguish melanoma from other melanocytic disorders, including pediatric Spitzoid tumors that are difficult to diagnose by conventional methods alone. In this report, we report a case of PRAME-expressing juvenile Spitzoid melanoma with lymph node metastasis. Unexpectedly, there were few PRAME-expressing cells in the primary tumor, whereas most metastatic tumors expressed PRAME in the metastatic lymph node. These observations might suggest that, in Spitzoid melanomas, a limited number of melanoma cells possess metastatic potential and that metastatic lesions possess clonality.

Dermatoscopic features of thin (≤2 mm Breslow thickness) vs. thick (>2 mm Breslow thickness) nodular melanoma and predictors of nodular melanoma versus nodular non-melanoma tumours: a multicentric collaborative study by the International Dermoscopy Society

BACKGROUND

Thin nodular melanoma (NM) often lacks conspicuous melanoma-specific dermatoscopic criteria and escapes clinical detection until it progresses to a thicker and more advanced tumour.

OBJECTIVE

To investigate the dermatoscopic morphology of thin (≤2 mm Breslow thickness) vs. thick (>2 mm) NM and to identify dermatoscopic predictors of its differential diagnosis from other nodular tumours.

METHODS

Retrospective, morphological case-control study, conducted on behalf of the International Dermoscopy Society. Dermatoscopic images of NM and other nodular tumours from 19 skin cancer centres worldwide were collected and analysed.

RESULTS

Overall, 254 tumours were collected (69 NM of Breslow thickness ≤2 mm, 96 NM >2 mm and 89 non-melanoma nodular lesions). Light brown coloration (50.7%) and irregular brown dots/globules (42.0%) were most frequently observed in ≤2 mm NMs. Multivariate analysis revealed that dotted vessels (3.4-fold), white shiny streaks (2.9-fold) and irregular blue structureless area (2.4-fold) were predictors for thinner NM compared to non-melanoma nodular tumours. Overall, irregular blue structureless area (3.4-fold), dotted vessels (4.6-fold) and serpentine vessels (1.9-fold) were predictors of all NM compared to non-melanoma nodular lesions.

LIMITATIONS

Absence of a centralized, consensus pathology review and cases selected form tertiary centres maybe not reflecting the broader community.

CONCLUSIONS

Our study sheds light into the dermatoscopic morphology of thin NM in comparison to thicker NM and could provide useful clues for its differential diagnosis from other non-melanoma nodular tumours.

Spitz nevus with unusual dermoscopic figures in an adult female

Spitz nevus is an important differential diagnosis of malignant melanoma, especially in young adults. This case provides a significant information about unusual dermoscopic features of adult Spitz nevus, which may reflect changes over the years.

Dermoscopy: A Review of the Structures That Facilitate Melanoma Detection

Melanoma is currently the fifth most common cancer in the United States, resulting in more than 9000 deaths each year. Despite numerous improvements in the management of advanced melanoma, the cornerstone to ensuring a cure remains early detection. Both patient and physician awareness regarding the signs and symptoms of early melanoma remain paramount. As a result, much effort has been and continues to be expended in developing and refining effective diagnostic algorithms to help identify melanomas and differentiate them from nevi, such as the ABCDE rule (A for asymmetry, B for border irregularity, C for color variegation, D for diameter >6 mm, and E for evolution in lesion size, shape, or color). To assist in the detection of more subtle melanomas requires technology to augment a visual examination. Toward this end, a simple instrument called a dermatoscope has transformed not only the appreciation of the morphology of melanoma but also its growth dynamics. The discipline of dermoscopy has improved the detection of melanoma and other skin cancers, has resulted in the detection of thinner melanomas, and has helped improve the ability to differentiate nevi (benign lesions) from melanomas, which, in turn, has resulted in fewer biopsies of benign lesions. Since patients often first present to their primary care physicians for their health-related concerns, it is imperative that primary care physicians be able to recognize the lesions that are suspicious for melanoma. This review is intended to introduce osteopathic physicians to the dermoscopic features associated primarily with melanomas located on nonglabrous skin.

Spitz Nevus and Other Spitzoid Tumors in Children. Part 2: Cytogenetic and Molecular Features. Prognosis and Treatment

Melanocytic neoplasms with spitzoid morphology (Spitz nevi, atypical Spitz tumors, and spitzoid melanomas) may be benign or malignant. Because the malignant potential of atypical Spitz tumors is uncertain, the proper therapeutic approach has been much debated over the years. Promising new techniques for molecular analysis have enabled better predictions of the biological behavior of these tumors. We review their cytogenetic features and prognosis and also provide an update of the most recent recommendations for management.

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

Paediatric melanoma is rare and challenging to diagnose. The three subtypes are Spitzoid melanoma, melanoma arising in a congenital melanocytic nevus, and conventional (also known as adult-type) melanoma. Spitzoid melanomas have characteristic histopathological and genomic aberrations. Despite frequent involvement of the sentinel lymph nodes, most cases have an uneventful clinical course. Among congenital nevi, the risk of melanoma varies by projected size in adulthood, with the greatest risk in large or giant nevi. The clinical course is generally aggressive and accounts for most melanoma-related deaths in childhood. In conventional melanoma, superficial spreading and nodular melanoma account for most cases, with risk factors and presentation largely similar to adult disease. In this Review, we discuss advances in histological diagnosis using adjunctive molecular assays, and summarise the genetic basis of paediatric melanoma.

Improvement of diagnostic confidence and management of equivocal skin lesions by integration of reflectance confocal microscopy in daily practice: Prospective study in 2 referral skin cancer centers

BACKGROUND

Reflectance confocal microscopy (RCM) allows accurate, noninvasive, in vivo diagnosis for skin cancer. However, its impact on physicians' diagnostic confidence and management is unknown.

OBJECTIVES

We sought to assess the physicians' diagnostic confidence and management before and after RCM of equivocal skin lesions.

METHODS

Prospective, 2-center, observational study. During clinical practice, 7 dermatologists recorded their diagnostic confidence level (measured in a scale from 0 to 10), diagnosis, and management before and after RCM of clinically/dermoscopically equivocal lesions that raised concern for skin cancer. We also evaluated the diagnostic accuracy before and after RCM.

RESULTS

We included 272 consecutive lesions from 226 individuals (mean age, 53.5 years). Diagnostic confidence increased from 6.2 to 8.1 after RCM (P < .001) when RCM confirmed or changed the diagnosis. Lesion management changed in 33.5% cases after RCM (to observation in 51 cases and to biopsy/excision in 31 cases). After RCM, the number needed to excise was 1.2. Sensitivity for malignancy before and after RCM was 78.2% and 85.1%, respectively. Specificity before and after RCM was 78.8% and 80%, respectively.

LIMITATIONS

Small sample size, real-life environment, and different levels of expertise among RCM users.

CONCLUSION

Physicians' diagnostic confidence and accuracy increased after RCM when evaluating equivocal tumors, frequently resulting in management changes while maintaining high diagnostic accuracy.

Clinical features and outcomes of spitzoid proliferations in children and adolescents

BACKGROUND

Spitzoid proliferations range from Spitz naevi to melanomas. There are few studies describing clinical features and outcomes in the paediatric population.

OBJECTIVES

To determine the clinical features and outcomes of a large paediatric cohort with histopathologically confirmed Spitz tumours.

METHODS

This was a retrospective cohort study of patients seen at Boston Children's Hospital who were aged < 20 years and had a histopathological diagnosis of spitzoid proliferation from 1 January 1994 to 23 October 2012.

RESULTS

In total 595 patients with 622 spitzoid proliferations were identified (median age 7·4 years, interquartile range 4·6-11·7). Overall 512 proliferations (82·3%) were typical, 107 (17·2.%) were atypical and three (0·5%) were melanomas. The median ages at biopsy were 7·4, 7·2 and 17·2 years, respectively, and there was a significant difference in age at biopsy for patients with typical or atypical proliferations vs. melanoma (P < 0·01). Among samples with positive margins (n = 153), 55% (54 of 98) of typical proliferations, 77% (41 of 53) of atypical proliferations and 100% (two of two) of melanomas were re-excised. Six patients had sentinel lymph node biopsy performed, with three patients demonstrating nodes positive for melanocytic cells. Within a median follow-up of 4·1 years for the full cohort there were no related deaths.

CONCLUSIONS

Spitz tumours have strikingly benign outcomes in the paediatric population, although this study is limited by the low number of melanomas and restriction to a single paediatric institution. Aggressive management recommendations should be reconsidered for children and adolescents with banal-appearing Spitz naevi, based on the clinically indolent behaviour in this cohort.

Clinicopathologically problematic melanocytic tumors: a case-based review

Background

In spite of recent advances in the histopathological and molecular diagnosis of melanocytic neoplasms, a certain proportion of these lesions remain a daunting challenge for both the clinician and the pathologist.

Objectives

To emphasize the importance of close collaboration between clinicians and pathologists in case of problematic melanocytic lesions.

Patients

We report and discuss 5 problematic scenarios of melanocytic lesions, including tumoral melanosis, nevoid melanoma, lentiginous melanoma, spitzoid melanoma and BAPoma that may pose diagnostic difficulties in our practice.

Conclusions

Clinico-dermoscopic-pathological correlation, with incorporation of all the available data, in problematic melanocytic skin neoplasms is of paramount importance for accurate diagnosis.

Sequential digital dermatoscopic imaging of patients with multiple atypical nevi

Patients with multiple atypical nevi are at higher risk of developing melanoma. Among different techniques, sequential digital dermatoscopic imaging (SDDI) is a state-of-the art method to enhance diagnostic accuracy in evaluating pigmented skin lesions. It relies on analyzing digital dermatoscopic images of a lesion over time to find specific dynamic criteria inferring biologic behavior. SDDI can reduce the number of necessary excisions and finds melanomas in an early—and potentially curable—stage, but precautions in selecting patients and lesions have to be met to reach those goals.

Recognition of early melanoma: a monocentric dermoscopy follow-up study comparing de novo melanoma with nevus-associated melanoma

BACKGROUND

The earlier detection of melanomas occurring within preexisting nevi is theoretically possible using sequential dermoscopy. Characterizing the early follow-up changes of nevus-associated melanomas (NAMs) and differentiating them from those observed in de novo melanomas (DNMs) may help the earlier recognition of NAMs.

METHODS

Using descriptive dermoscopic features to detect focal changes, we blindly evaluated retrospectively the baseline and follow-up images of 32 melanomas that were subsequently classified as histopathologically defined NAMs or DNMs.

RESULTS

Correlates of growth, as structureless brown‐black areas or clods, complemented each other for the identification of DNMs at baseline (structureless brown‐black areas: 66.7% DNMs, 15% NAMs, P < 0.01; combined with clods, one or the other being present: 100% DNMs, 30% NAMs, P < 0.01) and when considering their baseline presence or their appearance at follow‐up (100% DNMs, 35% NAMs, P < 0.01). Correlates of fibrosis, as white lines, when considering their baseline presence or their appearance at follow-up, were associated with NAMs (60%, 16.7% DNMs, P = 0.027).

CONCLUSION

Significant differences, distinguishing NAMs from DNMs, were detected particularly when considering both baseline signs and follow-up changes. Earlier identification of NAMs and their subsequent improved histological characterization will help define the subgroup of high-risk patients, for whom comprehensive image monitoring may be beneficial.

Dermoscopy of a Spark's nevus

Spark’s nevus is a particular type of melanocytic nevus that on histology shows features of both Spitz’s and Clark’s nevus. Clinically, it is an asymmetric, irregular, multicolored, pigmented lesion that is not clearly distinguishable from melanoma or dysplastic (Clark’s) nevus. Dermoscopic features have not been described yet, and one could speculate that they are similar to those of Clark’s nevi because the histopathologic architecture of Spark’s nevus is similar to that of a Clark’s nevus, resembling Spitz’s nevi in the epithelioid morphology of melanocytes. We present a 32-year-old woman with a Spark’s nevus, who upon dermoscopy showed a pronounced atypical network with accentuation of the blue veil and mostly peripheral dots.

The limitations of dermoscopy: false-positive and false-negative tumours

Dermoscopy has been documented to increase the diagnostic accuracy of clinicians evaluating skin tumours, improving their ability to detect skin cancer and better recognize benign moles. However, dermoscopically 'false-positive' and 'false-negative' tumours do exist. False-positive diagnosis usually leads to unnecessary excisions. False-negative diagnosis is much more dangerous, as it might result in overlooking a cancer, with severe undesirable consequences for the patient and the physician. Therefore, management strategies should mainly focus on addressing the risk of dermoscopically false-negative tumours. The most frequent benign tumours that might acquire dermatoscopic characteristics suggestive of malignancy are seborrhoeic keratosis (SK), including solar lentigo, melanoacanthoma, irritated, clonal and regressive SK, angioma (mainly thrombosed angioma and angiokeratoma), dermatofibroma, benign adnexal tumours and naevi (Clark, Spitz, recurrent, combined, sclerosing). The most useful clues to recognize these tumours are the following: solar lentigo - broad network; melanoacanthoma - sharp border; irritated SK - regularly distributed white perivascular halos; clonal SK - classic SK criteria; regressive SK - remnants of SK; targetoid haemosiderotic haemangioma - dark centre and reddish periphery; thrombosed angioma - sharp demarcation; angiokeratoma - dark lacunae; atypical dermatofibromas - palpation; follicular tumours - white colour; sebaceous tumours - yellow colour; Clark naevi - clinical context; Spitz/Reed naevi - age; combined naevi - blue central area; recurrent naevi - pigmentation within the scar; sclerosing naevi - age and location on the upper back; blue naevi - history. Malignant tumours that might mimic benign ones and escape detection are melanoma (in situ, nevoid, spitzoid, verrucous, regressive, amelanotic), squamous cell carcinoma (mainly well-differentiated variants) and rarely basal cell carcinoma (non-pigmented variants). The most useful clues to recognize the peculiar melanoma subtypes are as follows: melanoma in situ - irregular hyperpigmented areas; nevoid melanoma - history of growth; spitzoid melanoma - age; verrucous melanoma - blue-black sign; regressive melanoma - peppering or scar-like depigmentation; amelanotic melanoma - pink colour, linear irregular vessels, dotted vessels. In this article, we summarized the most frequent dermoscopic variations of common skin tumours that are often misinterpreted, aiming to assist clinicians to reduce the number of false diagnoses.