Malignant melanoma in childhood: a clinicopathologic study of 13 cases and comparison with Spitz nevi

Melanoma in children: A systematic review and individual patient meta-analysis

The current evidence on paediatric melanoma is heterogeneous, especially regarding the prognosis of different histological subtypes. We sought to systematically review the evidence on paediatric melanoma, highlighting the major sources of heterogeneity and focusing on available data on single patients. A systematic search was performed from 1948 to 25 January 2021. Only studies reporting at least one case of cutaneous melanoma in patients aged ≤18 years were included. Unknown primary and uncertain malignant melanomas were excluded. Three couples of authors independently performed title/abstract screening and two different authors reviewed all the relevant full texts. The selected articles were manually cross-checked for overlapping data for qualitative synthesis. Subsequently data on single patients were extracted to perform a patient-level meta-analysis. PROSPERO registration number: CRD42021233248. The main outcomes were melanoma-specific survival (MSS) and progression-free survival (PFS) outcomes. Separate analyses were done of cases with complete information on histologic subtype, focusing on superficial spreading (SSM), nodular (NM) and spitzoid melanomas, as well as of those classified as de-novo (DNM) and acquired or congenital nevus-associated melanomas (NAM). The qualitative synthesis covered 266 studies; however, data on single patients were available from 213 studies including 1002 patients. Among histologic subtypes, NM had a lower MSS than both SSM and spitzoid melanoma, and a lower PFS than SSM. Spitzoid melanoma had a significantly higher progression risk than SSM and trended toward lower mortality. Focusing on nevus-associated status, DNM demonstrated better MSS after progression than congenital NAM, and no differences were highlighted in PFS. Our findings describe the existence of different biological patterns in paediatric melanoma. Specifically, spitzoid melanomas demonstrated intermediate behaviour between SSM and NM and showed a high risk of nodal progression but low mortality. This raises the question of whether spitzoid lesions are being over-diagnosed as melanoma in childhood.

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.

A Practical Approach to the Diagnosis of Melanocytic Lesions

CONTEXT.—

Melanocytic lesions are common in routine surgical pathology. Although the majority of these lesions can be confidently diagnosed using well-established morphologic criteria, there is a significant subset of lesions that can be diagnostically difficult. These can be a source of anxiety for patients, clinicians, and pathologists, and the potential consequences of a missed diagnosis of melanoma are serious.

OBJECTIVE.—

To provide a practical approach to the diagnosis of melanocytic lesions, including classic problem areas as well as suggestions for common challenges and appropriate incorporation of ancillary molecular techniques.

DATA SOURCES.—

Literature search using PubMed and Google Scholar, incorporating numerous search terms relevant to the particular section, combined with contemporaneous texts and lessons from personal experience.

CONCLUSIONS.—

Although a subset of melanocytic lesions can be diagnostically challenging, the combination of a methodical approach to histologic assessment, knowledge of potential diagnostic pitfalls, opinions from trusted colleagues, and judicious use of ancillary techniques can help the pathologist navigate this difficult area.

Pathology and genomics of pediatric melanoma: A critical reexamination and new insights

The clinicopathologic features of pediatric melanoma are distinct from those of the adult counterpart. For example, most childhood melanomas exhibit a uniquely favorable biologic behavior, save for those arising in large/giant congenital nevi. Recent studies suggest that the characteristically favorable biologic behavior of childhood melanoma may be related to extreme telomere shortening and dysfunction in the cancer cells. Herein, we review the genomic profiles that have been defined for the different subtypes of pediatric melanoma and particularly emphasize the potential prognostic value of telomerase reverse transcriptase alterations for these tumors.

Melanoma in children

CONTEXT

Cutaneous melanoma in childhood (CMC) is rare; therefore, its prognostic factors and biologic behavior, and the effectiveness of adjuvant techniques for CMC remain mostly unknown.

OBJECTIVE

To review the most useful, evidence-based practice criteria for establishing the diagnosis of CMC, for which universally accepted criteria are lacking, in order to facilitate the interpretation and comparison of the results from different institutions, and to perform systematic reviews and meta-analysis.

DATA SOURCES

A comprehensive review of the most relevant previous single-institution series reported in the literature since 1990, including our cumulative experience of 137 cases of primary cutaneous and mucosal melanoma in patients younger than 18 years. Special characteristics of melanoma in children are discussed, regarding clinical settings and risk factors, helpful histologic features, and immunohistochemical patterns for diagnosis and prognosis.

CONCLUSIONS

Careful analysis of histologic features as well as the additional information provided by immunohistochemistry should allow for a correct diagnosis in most cases of melanoma in children. Although it seems that pediatric patients with melanoma have higher survival probability than adults, still a number of children will develop metastasis and die of their disease, particularly when melanoma is diagnosed after puberty. Until further studies more accurately determine the prognosis, a prudent approach to CMC diagnosis and therapy seems to follow the same principles as those established for adult melanoma.

Prognostic factors for melanoma in children and adolescents: a clinicopathologic, single-center study of 137 Patients

BACKGROUND

Cutaneous melanoma in childhood is rare; therefore, its prognostic factors and biologic behavior and the effectiveness of adjuvant diagnostic techniques in this group remain mostly unknown.

METHODS

The authors conducted a retrospective, observational study on the prognostic significance of clinical and pathologic findings from 137 cutaneous and mucosal melanomas in patients aged <18 years that were reviewed by the pathology department of a large cancer center during the period from 1992 to 2006.

RESULTS

Univariate analysis indicated that there was a significantly greater risk of metastases for patients who had previous nonmelanocytic malignancies, nodular histologic type, fusiform or spitzoid cytology, high Breslow thickness, vertical growth phase, high dermal mitotic activity, ulceration, and vascular invasion. Adjacent nevus and radial growth phase were associated with a better prognosis. Twelve patients (10.3%) died during follow-up. Decreased overall survival was related significantly to age >10 years, previous nonmelanocytic malignancy, high Breslow thickness, high Clark level, and the presence of metastases at diagnosis. All patients who died were aged ≥ 11 years, and 8 of those patients had metastases at diagnosis. In multivariate analysis, higher Breslow thickness predicted an increased risk of metastases, whereas age >10 years and the presence of metastases at diagnosis were associated with decreased survival.

CONCLUSIONS

Similar to adults, the detection of metastases at diagnosis in children with melanoma was 1 of the main factors that influenced overall survival. Melanomas that were detected in children aged <11 years appeared to have a less aggressive behavior than those detected in adults.

Comparison of pHH3, Ki-67, and survivin immunoreactivity in benign and malignant melanocytic lesions

Differentiating malignant melanoma from benign melanocytic lesions can be challenging. We undertook this study to evaluate the use of the immunohistochemical mitosis marker phospho-Histone H3 (pHH3) and the proliferation markers Ki-67 and survivin in separating malignant melanoma from benign nevi. Sixty-six melanocytic lesions (18 malignant melanomas, 8 Spitz nevi, 20 dysplastic nevi, and 20 compound nevi) were stained with antibodies to pHH3, Ki-67, and survivin. No pHH3 expression was detected in the dermis of compound and dysplastic nevi. Rare mitoses were observed in the superficial dermis in 3 of 8 Spitz nevi (37%). Staining for pHH3 was higher in malignant melanomas [average 25 per 10 high-power field (HPF), range 2-75 per 10 HPF] than in Spitz nevi (average 0.5 per 10 HPF, range 0-2 per 10 HPF) and was heterogeneously distributed in the malignant melanomas compared with a superficial dermal location in Spitz nevi. There was no cytoplasmic staining for survivin in any of the 66 melanocytic lesions and no nuclear staining in any of the benign ones. Survivin nuclear staining was present in 12 of 18 cases of malignant melanoma (67%) with an average index of 7% (range 0%-15%). In benign melanocytic lesions, the Ki-67 index was less than 5% (range 0%-4%) and staining was present close to the dermo-epidermal junction compared with an average index of 27% in melanomas (range 5%-50%) and a generally heterogeneous pattern of staining throughout the dermis. pHH3 and Ki-67 can be useful adjuncts to histopathology to separate malignant melanoma from benign nevi. pHH3 is especially useful to highlight mitoses and to rapidly assess the mitotic activity in melanocytic lesions.

Sentinel lymph node biopsy in histologically ambiguous melanocytic tumors with spitzoid features (so-called atypical spitzoid tumors)

BACKGROUND

The distinction of Spitz nevi from melanomas with spitzoid morphology can be difficult. For lesions with overlapping histopathologic features, it may be impossible to predict their malignant potential with certainty. The current study evaluated the role of sentinel lymph node (SLN) biopsy in patients with such atypical spitzoid tumors.

METHODS

The clinical and histopathologic features of 21 patients with atypical spitzoid tumors who underwent SLN biopsy were reviewed and correlated with the presence or absence of metastatic tumor in their corresponding SLNs.

RESULTS

The atypical histopathologic features that were most frequently present included incomplete maturation (11 patients, 52%), two or more dermal mitoses per square millimeter (13 patients, 62%), and deep dermal mitoses (11 patients, 52%). Six patients (29%) showed SLN metastasis. There were histopathologic differences between tumors with positive SLN when compared with tumors with negative SLN: mean tumor thickness (3.38 mm vs. 2.04 mm), incomplete maturation (83% vs. 40%), median dermal mitotic rate (3.5/mm(2) vs. 2/mm(2)), deep dermal mitoses (83% vs. 47%), and expansile dermal nodules (50% vs. 13%). However, of these, only the difference in mean tumor thickness reached statistical significance (P < .05).

CONCLUSIONS

SLN biopsy offers a means of assessing the metastatic potential of atypical spitzoid tumors and aids in the management of these patients by selecting patients who may benefit from a regional node field dissection and those in whom the use of adjuvant therapies could be considered.

BRAF and NRAS mutations in spitzoid melanocytic lesions

BRAF mutations are common events in a variety of melanocytic nevi and primary cutaneous melanomas. We have previously found BRAF mutations in 82% of nevi, consisting of congenital, common acquired and dysplastic types, and 33% of primary cutaneous melanomas other than the spitzoid type, similar to other published reports. A small number of studies have evaluated Spitz nevi and have failed to detect any lesions possessing a BRAF mutation. Only one study included categories of atypical Spitz nevus and borderline lesions suspected to be spitzoid melanomas, along with classic Spitz nevi and spitzoid melanomas. We examined a spectrum of spitzoid lesions that included 48 Spitz nevi, some with atypical features, seven atypical (borderline) Spitz tumors, and 13 spitzoid melanomas. BRAF mutations were detected in 12 of 68 spitzoid lesions, of which two were spitzoid melanomas and 10 were Spitz nevi. Five of the 10 Spitz nevi with BRAF mutations were altered by more than usual cytologic atypia and/or architectural atypia overlapping with dysplastic nevi, or irritation/inflammation; one desmoplastic Spitz nevus had a BRAF mutation. These results indicate that a small subset of Spitz nevi, some with atypical histologic features, possess BRAF mutations. Therefore, the BRAF mutational status does not separate all Spitz nevi from spitzoid melanomas and non-Spitz types of melanocytic proliferations, contrary to previous reports.

Does melanoma behave differently in younger children than in adults? A retrospective study of 33 cases of childhood melanoma from a single institution

OBJECTIVE

To ascertain whether childhood melanoma presents any peculiar clinical features or differences in prognosis with respect to adults, we retrospectively analyzed the data from 33 patients who were up to 14 years of age and treated for cutaneous melanoma at the Istituto Nazionale Tumori, Milan, over a 25-year period.

METHODS

Primary lesions were amelanotic in half of the cases and raised in 73%. Lower extremities were the most common primary sites. Histologically, 9 cases were classified as nodular type, and median thickness was 2.5 mm. Nine children had nodal involvement at diagnosis, 2 in-transit metastases, and 1 distant spread. Surgery was the mainstay of treatment; 9 patients underwent lymph node dissection, 3 received chemotherapy, and 2 received radiotherapy.

RESULTS

With a median follow-up of 122 months, 5-year event-free survival and overall survival were 60% and 70%, respectively. Age seemed to correlate with survival, event-free survival being 90% in children under 10 and 47% in older patients, although the initial microstaging seemed worse in the former.

CONCLUSION

By comparison with adult cases, childhood melanoma can have a higher percentage of atypical clinical features (amelanotic and raised lesions), nodular histotype, and thick lesions. Although we have no data to support any suggestion of biological differences between young children and adolescents or adults, our findings give the impression that melanoma behaves differently in the younger age group.

Common and uncommon variants of melanocytic naevi

Numerous variants of melanocytic naevi have been described. Their main pathological significance lies in their distinction from melanoma, as well as being precursors and risk markers for melanoma. Various degrees of atypia such as cytological atypia, architectural disorder and pagetoid spread (pagetoid melanocytosis) may be present in naevi and need to be recognised as appropriate for the subtype. As well as the distinction from melanoma, naevi must be differentiated from atypical lesions, such as atypical Spitz tumours, which do not fulfil all the criteria of melanoma, may be benign or malignant and have been called 'melanocytic tumours of unknown malignant potential'. The diagnostic grey area also includes a group of benign atypical naevi which are difficult to subclassify into specific entities. In this paper naevi are divided into: firstly, the common acquired group with a brief discussion of junctional, compound and intradermal naevi, minor variants such as halo and balloon naevi and the major variants that may cause problems -- dysplastic naevi, naevi of special sites, recurrent naevi and Spitz naevi; secondly, congenital naevi; thirdly, blue naevi and related lesions (dermal melanocytoses); and finally, combined naevi. The emphasis is on diagnostic pathological features and the differential diagnosis with melanoma.

Melanomas in prepubescent children: review comprehensively, critique historically, criteria diagnostically, and course biologically

Our series was comprised of 11 children age 10 years or younger (6 were younger than age 5) with primary cutaneous melanoma. All of the melanomas occurred de novo and all metastasized; one child died. In no instance was melanoma a clinical consideration, and in none did the histopathologist who first "signed out" the case make a diagnosis of melanoma. Despite the inability of clinicians and pathologists to diagnose correctly, with repeatability, melanomas that develop in children yet to be pubescent, those neoplasms, nonetheless, are melanomas and, therefore, criteria employed currently for diagnosis of melanoma, especially clinically, must be refined in order that they be applicable equally to melanomas in pre- and postpubescents. The vaunted ABCDs (Asymmetry, Border irregular, Color variability, Diameter >6.0mm) surely do not work for melanomas that appear in children who are prepubescent. Additionally, melanomas that occur in these children have distinctly different architectural and cytopathological features from those that arise in postpubescents, often being confused as they are by conventional microscopy with a Spitz's nevus. As a rule, melanomas in prepubescent children grow much more rapidly then those in adults but, like them, have the capability to disseminate widely and cause death.

Malignant melanoma in an 8-year-old Caribbean girl: diagnostic criteria and utility of sentinel lymph node biopsy

The incidence of malignant melanoma (MM) is continuing to rise, although childhood MM remains rare. We describe an 8-year-old Afro-Caribbean girl who developed a non pigmented lesion on the tip of her left thumb, which persisted despite treatment in primary care with cryotherapy. At biopsy she was found to have an acquired acral MM. She underwent amputation of the distal phalanx of her thumb, together with positive sentinel lymph node (SLN) biopsy and subsequent axillary lymph node clearance and adjuvant chemotherapy. MMs are very rare in this age and skin-type group, therefore requiring strict diagnostic criteria. These criteria include the distinction from MM mimics, especially Spitz tumours, and an appropriate use of staging techniques such as SLN biopsy to influence management.

Sentinel lymph node biopsy for patients with problematic spitzoid melanocytic lesions: a report on 18 patients

BACKGROUND

Spindle and/or epithelioid melanocytic proliferations that display overlapping histopathologic features of Spitz nevus and Spitz-like melanoma are diagnostically difficult and controversial melanocytic tumors. There are reports of such lesions metastasizing to regional lymph nodes, with a few widely disseminating, resulting in death.

METHODS

The authors reviewed clinical and histopathologic data on all patients with atypical or borderline spitzoid melanocytic proliferations who underwent sentinel lymph node biopsy (SLNB). They examined how frequently histologically problematic or borderline spitzoid melanocytic lesions metastasized to sentinel lymph nodes (SLNs) and which clinical or histologic features, if any, predisposed patients to a higher risk lesion.

RESULTS

Six male patients and 12 female patients, ages 5-32 years (mean, 16 years), had tumors ranging in size from 1.2 mm to 7.9 mm (mean, 3.5 mm) in thickness. Atypical histologic features that were present most frequently included incomplete maturation (18 of 18 patients), deep dermal mitoses (16 of 18 patients), nuclear pleomorphism (10 of 18 patients), and focal sheet-like growth (10 of 18 patients). Eight of 18 patients (44%) had SLN metastasis and were offered adjuvant treatment. One of eight patients with SLN positive results who underwent regional lymphadenectomy had one additional involved lymph node. All 18 patients were alive and well with no evidence of recurrent or metastatic disease after a follow-up of 3-42 months (mean, 12 months).

CONCLUSIONS

Histologically atypical or borderline spitzoid, melanocytic tumors are diagnostically challenging and controversial melanocytic lesions, some of which represent unrecognized melanomas. SLNB aids in confirming a diagnosis of melanoma and identifies patients who may benefit from early therapeutic lymph node dissection and/or adjuvant therapy.

The surgical management of Spitz nevi

BACKGROUND

The biologic behavior of Spitz nevi and atypical Spitz nevi ranges from completely benign to the rare malignant melanoma. Various recommendations for the surgical approach to these lesions have been proposed.

OBJECTIVE

To determine any trend in the surgical management of Spitz nevi and atypical Spitz nevi among a community of dermatologists.

METHODS

Retrospective review of the clinical features, surgical management and outcome of 89 patients with the diagnosis of Spitz nevus or atypical Spitz nevus.

RESULTS

All biopsy techniques had a high incidence of involved margins: shave (67%), excision (28%), and punch (21%). Of the atypical Spitz nevi with positive margins on biopsy, there was a trend (7/9) toward reexcision with narrow margins (average 2.2 mm).

CONCLUSION

The majority of atypical Spitz nevi incompletely removed by biopsy were excised with narrow uncontrolled margins. A stratified surgical approach depending on the clinical and histopathologic features of the Spitz lesion is proposed. More aggressive surgical management of Spitz lesions with atypical features may be warranted. Further studies to determine the biologic potential of these lesions are needed.

Management of Spitz nevi: a survey of dermatologists in the United States

BACKGROUND

There is no consensus concerning management of Spitz nevi.

OBJECTIVE

This study was carried out to ascertain how dermatologists manage Spitz nevi.

METHODS

A questionnaire was sent to 997 fellows of the American Academy of Dermatology, 284 pediatric dermatologists, and 27 directors of pigmented-lesion clinics. The results are based on the 381 questionnaires returned.

RESULTS

The vast majority of responding dermatologists (93%) recommend biopsies of suspected Spitz nevi. Of this group, 43% recommend total biopsies and 55% recommend partial biopsies; 2% would recommend either total or partial biopsies, depending on the clinical situation. Sixty-nine percent of physicians would completely excise a lesion that was histologically diagnosed as an incompletely removed Spitz nevus. Seventy percent of general dermatologists and 80% of pediatric dermatologists would recommend excision with a 1- to 2-mm margin of normal-appearing skin around a Spitz nevus. Nine percent of general dermatologists would recommend margins of 4 mm or more; however, all pediatric dermatologists surveyed would recommend margins less than 4 mm. Physicians were less likely to monitor patients whose Spitz nevi were completely removed. Three fourths (74%) of respondents believe Spitz nevi are entirely benign, 4% believe they are precursors to melanoma, and 22% are not sure. Seven percent of general dermatologists and 4% of pediatric dermatologists have seen metastatic melanomas arise at sites of lesions initially diagnosed histologically as Spitz nevi; 40% of pigmented-lesion clinic directors have seen such lesions.

CONCLUSIONS

We believe that the lack of consensus, both in our survey and in the medical literature, reflects to some extent the lack of certainty in the histologic differentiation of Spitz nevi from melanomas and that concern about melanoma influences management. At the pigmented-lesion clinic of the New York University Skin and Cancer Unit, because of this concern about melanoma, it is usually recommended that Spitz nevi be completely excised.

Cutaneous melanoma in childhood and adolescence: an analysis of 36 patients

Analysis of data of 6931 patients with cutaneous melanoma seen at the Department of Dermatology and Allergology at the Ludwig-Maximilians-University of Munich between 1977 and 1998 identified 36 patients in whom cutaneous melanomas developed during childhood or adolescence (age <18 years). Clinical courses of all patients and histopathologic characteristics of the lesions were reviewed. Seventeen patients were boys and 19 patients were girls. The median ages of the boys and girls were 15 and 16 years, respectively (range, 2-17 years). Thirty-one patients presented with nonmetastatic primary melanomas and 5 patients presented with metastatic melanoma. Forty-seven percent of the primary lesions were associated with a nevus (22% with congenital nevi and 25% with acquired nevi). Tumor thickness ranged from 0.24 to 7.0 mm, with a median of 1.29 mm (mean, 1.67 mm). All patients with primary melanomas received surgical therapy; patients with metastatic disease received chemotherapy, radiation therapy, or both. Relative 5-year survival was 87.5% for the group of patients younger than 18 years. Similar to experience in adult patients, survival strongly correlated with tumor thickness and clinical stage at the time of diagnosis. The data emphasize that a high index of suspicion for cutaneous melanoma is needed by clinicians assessing melanocytic lesions in children and adolescents for early diagnosis. Reduction of the melanoma mortality rate in children and adolescents will be achieved through identification of patients at increased risk.

Spitz naevus versus Spitzoid melanoma: when and how can they be distinguished?

Spitz naevus is a benign melanocytic lesion that shares many histological features with melanoma. While Spitz naevi characteristically occur in children and young adults and melanomas in the middle-aged and elderly, either tumour can occur in patients of any age. In many cases, the histopathological diagnosis of Spitz naevus is straightforward, particularly in small lesions displaying many or all of the typical histological features and occurring in young patients. Tumours that deviate from the classic description, however, cause difficulties in diagnosis. In this review, we highlight histopathological features of Spitz naevi and those that may be useful in distinguishing Spitz naevi from melanomas. We find that the presence of good symmetry, Kamino bodies, and uniformity of cell nests or sheets from side-to-side favours a Spitz naevus. The presence of abnormal mitoses, a dermal mitotic rate of >2/mm2, and mitotic figures within 0.25 mm of the deep border of the lesion favours a melanoma. Immunohistochemical stains for HMB45 and Ki67 sometimes provide additional useful information. Despite this, in some cases it may not be possible to give an unequivocal diagnosis. Recommendations for the reporting of such cases are provided. New techniques have also demonstrated chromosomal, molecular and genetic differences between Spitz naevi and melanomas. This report highlights these new data and speculates on their possible future role in the diagnosis of borderline lesions.

Sentinel lymph node biopsy in patients with diagnostically controversial spitzoid melanocytic tumors

Melanomas can be difficult to diagnose histologically if they deviate in their growth pattern or cytology only minimally from a nevus. On occasion, even experts on melanocytic lesions may not reach a consensus on whether a lesion is a benign but unusual nevus or a malignant melanoma mimicking a nevus. This diagnostic dilemma is particularly well known for the distinction of Spitz nevus from melanoma. Diagnostic uncertainty and disagreement among consultant pathologists lead to confusion about the prognosis and clinical management of patients. In this study we present the clinical and pathologic findings of 10 patients with diagnostically controversial melanocytic tumors, who underwent sentinel lymph node biopsy. In all of these cases, the diagnostic controversy among experts was between Spitz nevus and melanoma. Seven patients were female, and three were male, ranging in age from 7 to 46 years (mean 21 years). Histologic examination of the sentinel lymph nodes revealed tumor deposits in the lymph node parenchyma in 5 of 10 patients. Among patients with positive sentinel lymph nodes, two had satellite nodules and one showed additional tumor deposits in three nonsentinel regional lymph nodes. All patients are alive and free of disease with a follow-up of 10-54 months (mean 34 months). Our study illustrates the role of a sentinel lymph node biopsy in the evaluation of patients with diagnostically controversial melanocytic tumors. Although the presence of metastatic tumor deposits in the sentinel lymph node supports the diagnosis of malignant melanoma, further studies are needed to determine the prognostic significance of the sentinel lymph node findings in such patients.

Spitzoid malignant melanoma in teenagers: an entity with no better prognosis than that of other forms of melanoma

AIMS

A rare form of melanoma in teenagers closely simulates Spitz naevus and is claimed to have a good prognosis. The aim of this study is to identify the clues for a confident diagnosis of this entity and to confirm the peculiarly good prognosis.

METHODS AND RESULTS

Two cases of melanoma with Spitzoid features were compared with Spitz naevus and it was found that the major distinctive criteria are: mitoses and single cell necrosis in the deepest part of the lesion, cellular and particularly nuclear and nucleolar pleomorphism, and growth pattern in solid sheets of cells. More subtle clues were the asymmetric distribution of pigment and the thinning of the epidermis with parakeratosis and exudate in the cornified layer. Both of the lesions reached the mid-dermis. There was a fatal outcome in both patients after generalized metastatic spread. The metastatic disease in one of the cases appeared 15 years after the excision of the primary lesion.

CONCLUSIONS

Spitzoid melanoma in teenagers can be distinguished from Spitz naevus if strict criteria are followed. Spitzoid melanoma does not show a better prognosis than other types of melanoma if the follow-up is prolonged enough.

Pediatric melanoma: confirming the diagnosis with sentinel node biopsy

Many pediatric melanoma lesions present at a more advanced stage than those in the adult population. Clinical and histological melanoma mimics, including a subset of Spitz nevi, are difficult to discriminate from melanoma. When dealing with a childhood melanoma, the clinician is likely to be faced with a thick lesion, and one in which the actual diagnosis may even be in doubt. There is a paucity of data to guide the physician in his management of melanoma in this age group, particularly with respect to node status and adjuvant therapy. The authors present two cases of pediatric melanoma in which the novel use of sentinel node biopsy helped confirm the diagnosis of melanoma, determined the need for full lymph node dissection, and guided the use of adjuvant interferon therapy.

A zonal comparison of MIB1-Ki67 immunoreactivity in benign and malignant melanocytic lesions

Differentiation between malignant melanomas and benign nevi can sometimes be difficult by conventional histopathology, and additional diagnostic markers may be helpful. This study investigated the immunoreactivity of the cell proliferation marker MIB1-Ki67 in 23 compound nevi, 17 dysplastic nevi, 8 Spitz nevi (SN), and 24 malignant melanomas (MMs) and evaluated its ability in separating benign nevi from MMs. In each lesion, the average number (percentage) of MIB1-positive nuclei (%MIB1-Mean) and the maximal number (percentage) of MIB1-positive nuclei (%MIB1-Max) were determined from each of the superficial, middle, and deep dermal zones of the lesion as well as from the entire lesion. The %MIB1-Max was determined from subjectively selected area(s) of high count. Malignant melanomas had a significantly greater %MIB1-Mean and %MIB1-Max than all benign nevi in all individual zones and in the entire lesion (p < 0.05). Discriminant analysis showed that the %MIB1-Mean and %MIB1-Max counted from the whole lesions had better discriminating abilities than from the individual zones. By using the %MIB1-Mean from all zones, all lesions except 1 SN and 3 MMs could be correctly classified as benign or malignant. When using the %MIB1-Max from all zones, all but 2 SN could be correctly separated as benign or malignant. Thus, MIB1-Ki67 immunoreactivity closely correlates with the benignancy or malignancy of melanocytic lesions and may assist in the differentiation of benign nevi from MMs.

Prepubertal malignant melanoma: report of three cases

Prepubertal malignant melanoma (MM) is an extremely rare tumor. In Slovenia, 13 MM cases were registered between 1968 and 1996 by the Cancer Registry of Slovenia. The diagnosis of MM was confirmed by histology in 3 children. In 3 other children the lesions initially diagnosed as MM were reclassified as Spitz nevus. In the remaining cases, the slides were not accessible for histological review, and the clinical course of disease corroborated the diagnosis of a benign nevus. In the present report, 3 of 13 cases with histologically confirmed prepubertal MM are described. The difficulties encountered in the diagnosis and management of this rare condition are discussed.

Atypical Spitz nevi/tumors: lack of consensus for diagnosis, discrimination from melanoma, and prediction of outcome

The biological nature of Spitz nevi/tumors and their diagnostic distinction from, or relationship to, melanoma remain unresolved issues. In this report, a series of 30 melanocytic lesions removed from 28 patients, including atypical Spitz nevi/tumors and metastasizing Spitzoid tumors/melanomas, were evaluated by a panel of dermatopathologists to evaluate interobserver diagnostic concordance and to assess the prognostic power of histological criteria. For inclusion in the study, each lesion had to display some criteria for the Spitz nevus, and in addition one of the following was required: (1) definitive clinical outcome such as metastasis or death of disease, or (2) long-term follow-up if the patient remained disease free. Each lesion was reviewed independently and blinded as to the clinical data by 10 pathologists, who categorized them as (1) typical Spitz nevus/tumor, (2) atypical Spitz nevus/tumor, (3) melanoma, (4) tumor with unknown biological potential, or (5) other melanocytic lesion. There was limited discussion of criteria before the review. Evaluation of 17 Spitzoid lesions yielded no clear consensus as to diagnosis; in only one case did six or more pathologists agree on a single category, regardless of clinical outcome. Notably, however, some lesions that proved fatal were categorized by most observers as either Spitz nevi or atypical Spitz tumors. Conversely, seven or more pathologists scored 13 lesions as melanoma. These results illustrate (1) substantial diagnostic difficulties posed by many Spitz tumors, especially those with atypical features, even among experts, and (2) the lack of objective criteria for their distinction from melanoma and for gauging their malignant potential. Nevertheless, our observations do suggest that a biological relationship exists between the Spitz nevus/tumor and melanoma.

Cutaneous malignant melanoma in Swedish children and teenagers 1973-1992: a clinico-pathological study of 130 cases

To assess whether there has been a change in histological features and prognostic factors of primary cutaneous malignant melanoma (CMM) in young individuals in Sweden, an unselected, population-based study was undertaken; 177 cases of primary CMM in persons below 20 years of age were reported to the Swedish National Cancer Registry between 1973 and 1992. In 87% of the cases, original tumor tissue was available for histo-pathological review. The original diagnosis was verified in 88% (n = 126) of these cases. All tumors had histological features similar to adult CMM; 17% had an associated precursor lesion. Superficial spreading melanoma (SSM) was the most common sub-type, constituting 20/36 cases in the first decade and 59/90 in the second. Corresponding figures for nodular melanoma (NM) were 11/36 and 23/90. Only 5 melanomas in situ were diagnosed. In girls, the mean thickness of SSM decreased from 1.5 to 0.6 mm (p < 0.001). Overall mortality was 10%, 22% in the group with CMM diagnosed 0-15 years of age and 8% in individuals 15-19 years. Fatal CMM cases diagnosed below 15 years of age (n = 4) were NM > 1.6 mm thick and in subjects 15-19 years (n = 9) 44% of fatal tumors were NM with a mean thickness of 2.2 mm. Breslow index was the single most important prognostic factor. However, when known prognostic factors were adjusted for in a Cox regression analysis, young age remained an independent risk factor, with a relative death rate of 0.21 for individuals aged 15-19 compared with children < 15 years of age.

Spitz nevus versus spitzoid malignant melanoma: an evaluation of the current distinguishing histopathologic criteria

Because of the well-known difficulty in distinguishing between Spitz nevi and spitzoid malignant melanomas at the microscopic level, the critical importance of this task notwithstanding, expert dermatopathologists across the world have strenuously endeavored to identify histopathologic criteria that would assist microscopists in this effort. Many reports itemizing such criteria are extant. The objective of the current study was to determine which of these criteria serve as the most consistent discriminators. Using a population of 11 spitzoid melanomas and 12 Spitz nevi, we evaluated six sets of criteria purported to be helpful in differentiating between these entities. Overall, we found that six features had significant distinguishing capacity, namely, (1) Kamino bodies, (2) a brisk mitotic rate, (3) mitoses close to the base of the lesion, (4) abnormal mitoses, (5) symmetry, and (6) uniformity of nests from side to side. It is noteworthy that the first three of these rank among the six criteria itemized repeatedly in 50% or more of the sets of criteria evaluated.

Cutaneous malignant melanoma in the young

Between the years 1967 and 1993, 3246 patients were diagnosed with malignant melanoma at Frenchay Hospital, Bristol. This paper reports 47 patients, 21 years of age or under, including 10 preadolescent cases under 14 years of age. It represents a further follow-up of a cohort originally published from this centre in 1986 in addition to 18 new cases. Most (89%) of the lesions occurred on the trunk and extremities, with females showing a predominance of lesions on the lower limbs. 83% of the melanomas were of the superficial spreading type: 72% invaded to Clark level III and IV. Thickness ranged from 0.29 mm to 50.00 mm (median 1.20 mm). Ulceration was present in 17% of cases and 32% of melanomas arose within a pre-existing small congenital melanocytic naevus. Overall 5-year survival was 81%, with a mean follow-up of 8.5 years. Ulceration and tumour thickness of greater than 1.5 mm were associated with a poor prognosis.

Melanoma in childhood: an EORTC-MCG multicenter study on the clinico-pathological aspects

Melanoma in children is rare. Nevertheless, it is imperative that clinicians be aware that melanoma does occur in childhood. Yet there is very little information available on the clinico-pathologic variations, and the prognostic parameters of melanoma in children. This report presents the results of a multicenter study of 102 lesions originally diagnosed as cutaneous melanoma, conducted among 5 Western European countries and collected during the period 1961-1994. Criteria for inclusion in the study included: (1) diagnosis of cutaneous melanoma; (2) age up to 16 years at diagnosis; and (3) availability of representative microscopic slides. On the basis of the histologic review only, 60 lesions were confirmed as melanoma, and 42 lesions initially diagnosed as melanoma were reclassified as nevi; 31 of the latter contained a predominance of spindle cells. The only significant parameter associated with the development of metatases or fatal outcome was thickness of more than 2.00 mm. The 5-year survival rate observed in this study was 84%. Based on these findings we conclude that considerable over-diagnosis of melanomas in children occurs. In order, therefore, to give consistent epidemiological data on melanomas in children and to improve proper recognition of their diagnostic features, both by clinicians and by pathologists, we propose to set up a central registry of melanomas in children in Europe, under the auspices of the European Organization for Research and Treatment of Cancer.

Incidence of cutaneous childhood melanoma in Queensland, Australia

The incidence of cutaneous melanoma in children aged 0-14 years was examined in Queensland, Australia. Details of notifications were collected from the population-based Australian Paediatric Cancer Registry. Between 1987 and 1994, the age-adjusted incidence rates of invasive cutaneous melanoma occurring in Queensland children were estimated at 8.5/million for males and 7.1/million for females. Incidence rates rose steeply in both sexes with increasing age, from less than 1/million in the 0-4 age group, to nearly 30/million in the 10-14 age group. To assess the uniformity of the anatomical distribution of lesions, relative tumour densities (RTDs) were calculated compared with the body as a whole. In both sexes, melanomas were most common on the trunk (RTD > 3), while lower limb lesions were less common (RTD < 0.6) and no melanomas were reported on the buttocks or external genitalia. Although not statistically significant, there was a tendency for truncal lesions in males to occur on the back, while in females, truncal melanomas were more evenly distributed across the chest, back and shoulders. No consistent relationship between latitude and melanoma incidence was observed, with higher rates reported in the subtropical than the tropical regions of Queensland. These are the first reported incidence rates of cutaneous melanoma in Australian children and are the highest ever reported in the world in this age group. Our findings provide baseline data from which to monitor changes in the occurrence of cutaneous melanoma in children.

Cutaneous melanoma and atypical Spitz tumors in childhood

BACKGROUND

Malignant melanoma in childhood is rare. As a result, the biology and natural history of melanoma in this age group is still poorly understood. Although the majority of Spitz nevi are benign regardless of atypical features, a particular problem is the continued confusion of Spitz nevi with atypical features with melanoma and the lack of specific criteria for their distinction. The latter discrimination is perhaps not so difficult when Spitz nevi are minimally atypical; however, the greater the atypia, the more challenging is this discrimination.

METHODS

All cases of malignant melanoma referred to Children's Hospital (Boston, MA) and to one of the authors were examined during the period of 1959-1995. Criteria for inclusion in the study included: (1) age up to 15 years; (2) availability of microscopic slides; and (3) availability of demographic data.

RESULTS

There were 11 males and 12 females, ranging in age from 2 to 15 years (mean age, 9.4 years). Histopathologically, the 23 tumors were categorized into four subgroups: (1) small cell melanoma (5); (2) adult-like melanoma (6); (3) Spitz-like melanoma (3), and (4) atypical Spitz tumors (9). The small cell melanomas were notable for localization to the scalp, significant thickness, and fatal outcome. The adult-like melanomas resembled typical tumors occurring in adults. The one fatal Spitz-like melanoma was located on the neck of a 14-year-old male. Two tumors in this group metastasized to regional lymph nodes, but were not associated with further aggressive disease on follow-up despite treatment with surgical excision only. The atypical Spitz tumors were characterized by significant thickness and abnormal features including prominent cellularity and mitotic activity.

CONCLUSIONS

Anatomic site and cell type may be important prognostic factors in addition to tumor thickness for childhood melanoma, but these tumors require further study. In addition, the biologic potential of atypical Spitz tumors has not been characterized sufficiently.

"Malignant Spitz nevus" in a 2-year-old Japanese child

Smith et al. (1989) have reported a variant of Spitz's nevus with histological atypical features. Despite local lymph node metastases, further metastases were not observed. They proposed the name "malignant Spitz nevus" for this variant. A 2-year-old Japanese girl had a large nodule (27 x 17 mm) surrounded by an indurated erythema over the Achilles tendon. Histologically, it proved to be a melanocytic lesion resembling spindle cell and epithelioid cell nevus (Spitz's nevus) with unusual features; the tumor extended deep into the subcutis, and the mitotic figures deep into the tumor, together with prominent lymphatic vessel invasion by melanocytes. Thus the tumor was aptly termed "malignant Spitz nevus". Flow cytometric analysis of the DNA content revealed a diploid pattern. The child is well 5 years after a wide resection of the tumor. The diploid pattern of the DNA content as well as the good prognosis could support the idea that "malignant Spitz nevus" fits within the spectrum of Spitz's nevus.

Childhood cutaneous melanoma

Seventeen consecutive patients no older than 14 years with cutaneous melanoma were observed from 1975 to 1991 at the Istituto Nazionale Tumori, Milan; this series represented 0.8% of all cutaneous melanomas observed at the Institute during this period. Ten were males and seven females. Nine lesions arose on limbs, seven on the trunk, and one on the head and neck area. Reexamination of the clinical records suggests that childhood melanoma may present with unusual characteristics such as unusual appearance of the primary lesion and lack or scarcity of pigmentation. At first observation ten patients had stage I disease nine underwent surgery alone while in one surgery was performed in combination with regional lymph node dissection and chemotherapy. All the stage II patients underwent excision of the primary lesion and lymph node dissection. One of the 2 stage III patients received lymph node dissection only, and the other no treatment. Analysis of this series of 17 cases does not indicate that cutaneous melanoma in children is more aggressive than in adults. It is stressed that, although rare, the physician should be aware that cutaneous melanoma may occur in prepuberty.

Cutaneous malignant melanoma in teenagers

Of 57 reviewed cases of malignant melanoma in teenagers, 51 had a minimum follow-up of 5 years. The histological and some clinical features of the 51 cases were compared for diagnostic and prognostic significance with those of 19 Spitz naevi and 10 other benign naevi using the SPSS-X computer program. The overall crude survival was 71% (males 64%, females 81%). Five patients with regional metastases survived more than 5 years, three of these more than 10 years. The main statistically significant features associated with a poor prognosis were Breslow thickness, diameter of ulcer, abnormal mitoses, pushing dermal borders and marginal (deep) mitoses. In comparison with Spitz naevi, features favouring malignancy were Breslow thickness, fine dusty cytoplasmic melanin pigment, marginal or abnormal mitoses, epithelioid intra-epidermal melanocytes below parakeratosis, dermal nests larger than junctional nests and the mitotic rate in the papillary dermis. Features favouring a benign lesion were diffuse maturation, spindle cells, spindle nuclei and Kamino bodies, especially if numerous or clustered. In comparison with the atypical benign naevi, significant features favouring malignancy were marginal or abnormal mitoses, single cell epidermal invasion below parakeratosis, large nuclei and irregular nuclei.