Dysplastic naevi and cutaneous melanoma risk

The role of reflectance confocal microscopy in differentiating melanoma in situ from dysplastic nevi with severe atypia: A cross-sectional study

BACKGROUND

Melanoma in situ and dysplastic nevi with severe atypia present overlapping histopathologic features. Reflectance confocal microscopy findings can be integrated with the dermatopathology report to improve differentiation between melanoma and dysplastic nevi with severe atypia.

OBJECTIVE

To compare prevalence of reflectance confocal microscopy findings between melanoma in situ and dysplastic nevi with severe atypia.

METHODS

This retrospective observational study compared reflectance confocal microscopy findings in dermatopathologically diagnosed dysplastic nevi with severe atypia and melanoma in situ, collected between 2007 and 2017 at a private pigmented-lesion clinic. Concordant pathologic diagnosis was defined as unanimous agreement between 3 dermatopathologists who independently reviewed all cases; all other cases were classified as discordant.

RESULTS

The study included 112 lesions, 62 concordant melanomas in situ, 28 concordant dysplastic nevi with severe atypia, and 22 discordant lesions. In comparing reflectance confocal microscopy findings in concordant cases, melanoma in situ showed more frequently than dysplastic nevi with severe atypia the presence of epidermal atypical melanocytes as round cells (19/62 vs 0/28; P < .001) and dendritic cells (50/62 vs 6/28; P < .001), as well as a diffuse distribution of epidermal atypical melanocytes (50/54 vs 3/6; P = .002). In contrast, dysplastic nevi with severe atypia showed the presence of dense melanocytic nests more frequently than melanoma in situ did (15/28 vs 14/62; P = .003).

LIMITATIONS

The study was based on a limited number of lesions originating from a single clinic.

CONCLUSIONS

Reflectance confocal microscopy findings may help differentiate a subset of dysplastic nevi with severe atypia from melanoma in situ.

Histologic mimics of malignant melanoma

Although spongiotic (eczematous), psoriatic and cutaneous skin infections are among the most common in dermatology consultations, melanocytic lesions - including the different types of nevi and melanomas - are among those that cause a great deal of concern and stress to patients and their clinicians. A diagnosis of benign melanocytic nevus carries a very good prognosis. However, a diagnosis of melanoma might indicate more aggressive treatment, lifelong surveillance and a worse prognosis. Differentiating between these conditions is not always a straightforward process for clinicians and pathologists. Therefore, knowledge of melanoma mimickers is very important for clinicians in general, and dermatologists and pathologists in particular. In this review, we called attention to some of the more frequent benign but unusual melanocytic lesions that are of diagnostic concern for clinicians evaluating these cutaneous proliferations.

Rare Variant, Gene-Based Association Study of Hereditary Melanoma Using Whole-Exome Sequencing

Background

Extraordinary progress has been made in our understanding of common variants in many diseases, including melanoma. Because the contribution of rare coding variants is not as well characterized, we performed an exome-wide, gene-based association study of familial cutaneous melanoma (CM) and ocular melanoma (OM).

Methods

Using 11 990 jointly processed individual DNA samples, whole-exome sequencing was performed, followed by large-scale joint variant calling using GATK (Genome Analysis ToolKit). PLINK/SEQ was used for statistical analysis of genetic variation. Four models were used to estimate the association among different types of variants. In vitro functional validation was performed using three human melanoma cell lines in 2D and 3D proliferation assays. In vivo tumor growth was assessed using xenografts of human melanoma A375 melanoma cells in nude mice (eight mice per group). All statistical tests were two-sided.

Results

Strong signals were detected for CDKN2A (Pmin = 6.16 × 10-8) in the CM cohort (n = 273) and BAP1 (Pmin = 3.83 × 10-6) in the OM (n = 99) cohort. Eleven genes that exhibited borderline association (P < 10-4) were independently validated using The Cancer Genome Atlas melanoma cohort (379 CM, 47 OM) and a matched set of 3563 European controls with CDKN2A (P = .009), BAP1 (P = .03), and EBF3 (P = 4.75 × 10-4), a candidate risk locus, all showing evidence of replication. EBF3 was then evaluated using germline data from a set of 132 familial melanoma cases and 4769 controls of UK origin (joint P = 1.37 × 10-5). Somatically, loss of EBF3 expression correlated with progression, poorer outcome, and high MITF tumors. Functionally, induction of EBF3 in melanoma cells reduced cell growth in vitro, retarded tumor formation in vivo, and reduced MITF levels.

Conclusions

The results of this large rare variant germline association study further define the mutational landscape of hereditary melanoma and implicate EBF3 as a possible CM predisposition gene.

Predictive Nuclear Chromatin Characteristics of Melanoma and Dysplastic Nevi

Background:

The diagnosis of malignant melanoma (MM) is among the diagnostic challenges pathologists encounter on a routine basis. Melanoma may arise in patients with preexisting dysplastic nevi (DN) and it is still the cause of 1.7% of all cancer-related deaths. Melanomas often have overlapping histological features with DN, especially those with severe dysplasia. Nucleotyping for identifying nuclear textural features can analyze nuclear DNA structure and organization. The aim of this study is to differentiate MM and DN using these methodologies.

Methods:

Dermatopathology slides diagnosed as MM and DN were retrieved. The glass slides were scanned using an Aperio ScanScopeXT at ×40 (0.25 μ/pixel). Whole slide images (WSI) were annotated for nuclei selection. Nuclear features to distinguish between MM and DN based on chromatin distributions were extracted from the WSI. The morphological characteristics for each nucleus were quantified with the optimal transport-based linear embedding in the continuous domain. Label predictions for individual cell nucleus are achieved through a modified version of linear discriminant analysis, coupled with the k-nearest neighbor classifier. Label for an unknown patient was set by the voting strategy with its pertaining cell nuclei.

Results:

Nucleotyping of 139 patient cases of melanoma (n = 67) and DN (n = 72) showed that our method had superior classification accuracy of 81.29%. This is a 6.4% gain in differentiating MM and DN, compared with numerical feature-based method. The distribution differences in nuclei morphology between MM and DN can be visualized with biological interpretation.

Conclusions:

Nucleotyping using quantitative and qualitative analyses may provide enough information for differentiating MM from DN using pixel image data. Our method to segment cell nuclei may offer a practical and inexpensive solution in aiding in the accurate diagnosis of melanoma.

Dysplastic nevus: why this term should be abandoned in dermatoscopy

The term "dysplastic nevus" is a misnomer and should be abandoned. Dysplastic nevus is not just a name, it is the root of the concept that histomorphology (or any morphologic examination including dermatoscopy) is able to predict the fate of a benign melanocytic proliferation. There is no evidence that this hypothesis is true but there are observations that falsify it. Preferably a specific diagnosis should be made based on dermatoscopic pattern and, if this is not possible, on clinical or dermatoscopic grounds alone the term "nevus, not otherwise specified" should be used.

Dermatology of the head and neck: skin cancer and benign skin lesions

Skin lesions are extremely common, and early detection of dangerous lesions makes skin cancer one of the most highly curable malignancies. By simply becoming aware of common lesions and their phenotypic presentation, dental professionals are empowered to detect suspicious dermatologic lesions in unaware patients. This article serves as an introduction to skin cancer and benign skin lesions for dental professionals.

Dysplastic nevi

Patients with multiple dysplastic nevi have an increased risk for malignant melanoma, and dysplastic nevi themselves have at least some potential for malignant transformation. Development of malignant melanoma is uncommon within dysplastic nevi, however. Since this transformation occurs in other types of nevi, their role as a marker of increased risk for melanoma in the patients who bear them seems to be of greater significance. This article discusses the gross, clinical and microscopic features; diagnosis; and prognosis of dysplastic nevi. The key features and pitfalls of diagnosing malignant melanoma, congenital nevus, and recurrent nevus are given.

Atypical mole syndrome and dysplastic nevi: identification of populations at risk for developing melanoma - review article

Atypical Mole Syndrome is the most important phenotypic risk factor for developing cutaneous melanoma, a malignancy that accounts for about 80% of deaths from skin cancer. Because the diagnosis of melanoma at an early stage is of great prognostic relevance, the identification of Atypical Mole Syndrome carriers is essential, as well as the creation of recommended preventative measures that must be taken by these patients.

Dysplastic Nevi

Patients with multiple dysplastic nevi have an increased risk for malignant melanoma, and dysplastic nevi themselves have at least some potential for malignant transformation. Development of malignant melanoma is uncommon within dysplastic nevi, however. Since this transformation occurs in other types of nevi, their role as a marker of increased risk for melanoma in the patients who bear them seems to be of greater significance. This article discusses the gross, clinical and microscopic features; diagnosis; and prognosis of dysplastic nevi. The key features and pitfalls of diagnosing malignant melanoma, congenital nevus, and recurrent nevus are given.

The prevalence of melanocytic naevi among schoolchildren in South Hungary

BACKGROUND

Malignant melanoma is an increasing public health problem worldwide; accordingly, identification of the constitutional and environmental factors which contribute to the development of the disease, and hence identification of the individuals at high risk of melanoma, is an indispensable step in all primary prevention efforts.

OBJECTIVES

This paper aims to assess the prevalence of different pigmented lesions among schoolchildren and to investigate their relationship with phenotypic pigmentary characteristics, sun exposure and other factors.

PATIENTS/METHODS

A cross-sectional study was performed in two secondary schools in Szeged, Hungary. A total of 1320 schoolchildren, aged 14 to 18 years, underwent a whole-body skin examination. A standardized questionnaire was used to collect data on phenotypic, sun exposure and other variables.

RESULTS

One to 10 common melanocytic naevi were found in 27% of the participants, and the naevus numbers were in the range of 10-100 in 67%; 5.4% of them had more than 100 common melanocytic naevi. The prevalence of clinically atypical naevi was 24.3%. Statistically significant associations were found between the number of pigmented lesions and gender, hair colour, eye colour, skin phototype, a history of severe painful sunburns and a family history of a large number of melanocytic naevi.

CONCLUSION

Our study population displayed a markedly high prevalence of clinically atypical melanocytic naevi. Moreover, a considerable proportion of the investigated individuals had multiple common melanocytic naevi. Since the presence of a large number of melanocytic naevi is a strong predictor for future melanoma development, health educational programmes on melanoma prevention should be aimed at young age groups.

Monitoring of Kindreds With Hereditary Predisposition for Cutaneous Melanoma and Dysplastic Nevus Syndrome: Results of a Swedish Preventive Program

Purpose

To evaluate a program initiated in 1987 by the Swedish Melanoma Study Group aiming to provide preventive surveillance to kindreds with hereditary cutaneous melanoma and dysplastic nevus syndrome.

Patients and Methods

Overall, 2,080 individuals belonging to 280 melanoma families were followed for 14 years between 1987 and 2001 at 12 participating centers. Data were registered in a central database.

Results

Among 1,912 skin lesions excised during follow-up, 41 melanomas were removed in 32 individuals. Of these, 15 (37%) were in situ melanomas and 26 (63%) invasive melanomas. The median tumor thickness of invasive melanomas was 0.5 mm. Ulceration was absent in 24 of 26 invasive melanomas (92%) and 12 (46%) lacked vertical growth phase. Compared with melanomas in the general Swedish population, the melanomas identified in these kindreds during follow-up had better prognostic characteristics. All melanomas except one were diagnosed in families with two or more first-degree relatives with melanoma. Diagnosis of melanoma occurred in three of eight kindreds with germline CDKN2A mutations, supporting that families with such mutations are at increased risk for melanoma development. Of the 32 individuals who developed melanoma during follow-up, 21 (66%) had had at least one previously diagnosed melanoma.

Conclusion

This study shows that a coordinated program aimed at detecting and offering skin surveillance in kindreds with hereditary cutaneous melanoma results in a low incidence of melanomas during the follow-up period and that the tumors that do arise have favorable prognostic characteristics.

Multiple common naevi in Israeli adolescents

The most prominent known phenotypic risk factor for the development of melanoma is a large number of common melanocytic naevi. The aims of this study were to determine the prevalence of multiple common naevi in a group of 17-year-olds and to identify possible associated risk factors. The study subjects were approximately 40,000 female and 60,000 male 17-year-old Jewish Israelis presenting to army recruitment centres for compulsory military service during a 1-year period from January 2003 to December 2003. Data were gathered on whole-body naevi count, years of education, place of residence and place of birth of the recruit, his/her parents and paternal grandparents. The count of whole-body naevi was carried out by military physicians. The multiple naevi phenotype was defined by the presence of more than 50 naevi. The prevalence of the phenotype was highest amongst recruits of American origin and lowest amongst those of Asian and African origin (P < 0.0001). The prevalence differed in different population centres, the highest being in the coastal cities of Haifa and Tel Aviv. This pattern corresponded to the geographical distribution of melanoma in Israel. Amongst male conscripts, the phenotype was more common in the better educated group (> or =12 years) than in the poorer educated conscripts (< or = 11 years) (P = 0.051). When adjusted for the factors studied, a significant correlation was found between a high multiple common naevi count and American and European origin and residence in coastal cities, reflecting the complex interplay between endogenous and exogenous factors of melanoma.

Assessment of 3 xeroderma pigmentosum group C gene polymorphisms and risk of cutaneous melanoma: a case-control study

Individuals with the rare DNA repair deficiency syndrome xeroderma pigmentosum (XP) are sensitive to the sun and exhibit a 1000-fold increased risk for developing skin cancers, including cutaneous melanoma. Inherited polymorphisms of XP genes may contribute to subtle variations in DNA repair capacity and genetic susceptibility to melanoma. We investigated the role of three polymorphic alleles of the DNA repair gene XPC in a hospital-based case-control study of 294 Caucasian patients from Germany who had cutaneous melanoma and 375 healthy cancer-free sex-matched Caucasian control subjects from the same area. We confirmed that the XPC intron 9 PAT+, intron 11 -6A, and the exon 15 2920C polymorphisms are in a linkage disequilibrium. Only 1.6% of the 669 donors genotyped were discordant for these three polymorphisms. The allele frequencies (cases: controls) were for intron 9 PAT+ 41.7%:36.9%, for intron 11 -6A 41.8%:37.0% and for exon 15 2920C 41.3%:37.3%. Using multivariate logistic regression analyses to control for age, skin type and number of nevi, the three polymorphisms were significantly associated with increased risks of melanoma: OR 1.87 (95% CI: 1.10-3.19; P = 0.022), OR 1.83 (95% CI: 1.07-3.11; P = 0.026), and OR 1.82 (95% CI: 1.07-3.08; P = 0.026), respectively. Exploratory multivariate analyses of distinct subgroups revealed that these polymorphisms were associated with increased risks for the development of multiple primary melanomas (n = 28). The results of our case-control study support the hypothesis that the intron 9 PAT+, intron 11 -6A and exon 15 2920C haplotype may contribute to the risk of developing cutaneous melanoma by increasing the rate of an alternatively spliced XPC mRNA isoform that skips exon 12 and leads to reduced DNA repair. Our results should be validated in independent samples in order to guard against false positive findings.

Acquired melanocytic nevi as risk factor for melanoma development. A comprehensive review of epidemiological data

Acquired melanocytic nevi (MN) in Caucasian populations are important markers for the risk of melanoma development. The total number of MN on the whole body is the most important independent risk factor for melanoma and the risk of melanoma development increases almost linearly with rising numbers of MN. Additionally, the presence of atypical MN and of actinic lentigines are likewise independent risk factors for melanoma. Atypical mole syndrome should be defined by the presence of many acquired MN and a threshold number of atypical MN. Acquired MN develops mainly during childhood and adolescence in the first two decades of life. The number of acquired nevi seems to be related to hereditary factors and nevus-prone families exist. The amount of sun exposure is the most important environmental risk factor for nevus development, particularly in early childhood. Interestingly, sunburns may play a role in nevus development, but seem not to be required, and even moderate sun exposure promotes the process. Therefore, preventive measures for nevus and melanoma development should target young children and adolescents.

Dermatological perspectives of malignant melanoma

Early recognition and treatment of thin cutaneous melanoma have contributed to a decreased case-fatality rate over the past 60 years. The only known preventive measure for melanoma is sun protection in childhood, which directly affects the number of melanocytic nevi developing as an adult. Additional melanoma risk factors, clinical features, and malignant potential of precursor lesions are discussed. The four major clinicopathologic subtypes of melanoma are described, with recommendations for appropriate biopsy techniques for suspected melanoma. Nationwide skin cancer screenings by dermatologists and greater public awareness of the warning signs of melanoma have enhanced detection of early melanoma, and promoted chances for cure.

Current concepts in the management of patients with melanoma

Melanoma is a significant health problem. Despite public education and free cancer screenings, the incidence and mortality of melanoma continues to rise; however, many currently diagnosed melanomas are thin lesions, suggesting that education and awareness is having an impact. In addition, there are still subsets of patients who need increased surveillance in order to increase their survival. Although large congenital nevi may be precursors of melanoma, small and medium congenital nevi have an insignificant risk for melanoma development. Large congenital nevi, which are axial in location, appear to be more likely to develop melanoma and are associated with melanocytosis and melanoma of the CNS, both of which portend a poor prognosis. Recently, the recommended margins of excision have become more conservative so that many of the surgical defects can be closed primarily. Lymphoscintigraphy and sentinel node biopsy have replaced elective node dissections, thus decreasing the morbidity associated with the surgical management of melanoma. Although controversy still exists as to whether or not sentinel lymph node biopsy alters a patient's prognosis, it has been shown to be a powerful prognostic indicator. Although most melanomas are managed by routine surgical excision, other modalities are sometimes employed. For example, cryosurgery or radiation therapy may be indicated in the frail, elderly individual with a large facial lentigo maligna. Mohs surgery is the treatment of choice for head and neck melanomas and those located in areas where maximum preservation of tissue is required and for desmoplastic and acral lentiginous melanomas. Much more work remains in the area of adjuvant therapy, chemotherapy, and immunotherapy. Dacarbazine remains the drug of choice in disseminated melanoma, but remissions are usually short lived. Interleukin and biochemotherapy has yielded good results but the percentage benefiting is small. Although high dose interferon increases disease-free and overall survival in some patients, it remains a controversial drug which is not easily tolerated. In the new staging system for melanoma, ulceration is second only to Breslow's thickness. In transit (satellite) lesions have also been included in this new system. The new system also recognizes that patients with only microscopic metastatic nodal disease fare better than patients with clinically enlarged metastatic nodes and that it is the number of nodes involved with metastases, not their size, that determines the patient's prognosis. Except for lesions <1mm thick, the Clark's level of invasion has been de-emphasized.

The pathology of malignant melanoma

It is clear that much of what has been taught over the years concerning the pathology of melanoma may have little validity. Melanoma is viewed simply as a malignant neoplasm comprised initially of a proliferation of atypical melanocytes within the surface epithelium (epidermis). It has many features in common, regardless of anatomic site. It spreads within the epidermis first for months, possibly years or even for decades. At this stage (melanoma in situ) it is wholly curable if completely surgically excised. What determines how long a given melanoma remains in situ is not clear. It is probably a combination of factors, including host response to the neoplasm; physical barriers to growth and metastasis (perhaps solar damage); chemical or humoral growth factors or inhibitors (perhaps genetically determined); and other as yet undiscovered factors. Once a given neoplasm penetrates into the subjacent dermis, there are whole ranges of ill-defined events that act on its ability to continue to grow and develop the competence for metastasis (growth factors and inhibitors, neoangiogenesis factors and inhibitors, host immune responses, and so forth). Let us throw out all of our prejudices that may have developed or nurtured over the years. There is much to learn about the pathobiology of melanoma. Clinicians should keep their minds open to new concepts and try to separate what makes sense from that which does not.

Expression of 12-lipoxygenase as a biomarker for melanoma carcinogenesis

12-Lipoxygenase (12-LOX), through its metabolite 12( )-hydroxyeicosatetraenoic acid [12( )-HETE], has been demonstrated to play a pivotal role in experimental melanoma invasion and metastasis, and 12-LOX expression may be important in early human melanoma carcinogenesis. We have studied the differences in 12-LOX protein expression during the progression of melanoma from human melanocytic cells to benign and dysplastic naevi to malignant metastatic disease. 12-LOX expression was determined in normal human skin melanocytes and in melanocytes found in compound naevi, dysplastic naevi and melanomas using a platelet-type 12-LOX antibody with a diaminobenzidine immunoperoxidase system detection system and was quantified using the analysis software NIH Image 1.62. Mean cellular pixel densities for 12-LOX staining ( = 50 cells/histological type) were unchanged in compound naevi ( = 0.14) and were increased in dysplastic naevi and melanomas compared with normal skin melanocytes ( = 0.03 and = 0.01, respectively). Similarly, melanomas had higher levels of expression compared with dysplastic naevi ( = 0.03). 12-LOX expression was significantly different between compound naevus and dysplastic naevus melanocytes ( = 0.01). These data suggest that 12-LOX may be an important novel marker for cancer progression within the melanoma system, and therefore could be a useful biomarker and therapeutic target for melanoma chemoprevention.

Hereditary cutaneous melanoma

Members of some kindreds have a hereditary predisposition for development of cutaneous melanoma. Cytogenetic and linkage studies implicated chromosomes 1p and 9p as possible locations for genetic alterations predisposing for melanoma. Germline mutations in the CDKN2A gene on chromosome 9p21 have been identified in hereditary melanoma, but are present in only approximately 40% of kindreds with linkage to 9p21, indicating that changes in other gene(s) at this location may also predispose to melanoma. In a few families, germline mutations in the CDK4 gene are present. The genetic alterations underlying disease predisposition in a large proportion of melanoma families remain unknown.

The frequency of histologically dysplastic nevi in 199 pediatric patients

Many uncertainties surround the definition, frequency, and significance of dysplastic nevi in children. Consequently the management of dysplastic nevi in the pediatric population has been largely derived from the studies of adults. Biopsies are usually performed on this young age group because of lesion change or abnormal appearance. One might therefore assume that the frequency of histologically diagnosed dysplastic nevi would be higher in children than in adults. We decided to attempt to verify this assumption by determining the frequency of dysplastic nevi diagnosed histologically in the pediatric population. To do this we reviewed 199 cutaneous pathology reports of nevi removed from patients less than 18 years old and submitted to a community-based dermatopathology laboratory. The diagnosis of dysplastic nevus was made based on histologic criteria recommended by the World Health Organization Melanoma Program. We found that 3 of 199 nevi submitted for histologic analysis met the histologic criteria for dysplastic nevus. There were no melanomas. Our data suggest that there is an extremely low frequency of histologically confirmed dysplastic nevi within the general pediatric population.

Chromosomal changes in dysplastic nevi

The dysplastic nevus is considered to be a precursor lesion of melanoma, representing one of the first steps in the progressive transformation from normal melanocyte to melanoma. Various risk degrees of developing cutaneous melanoma in patients with dysplastic nevi have been advanced, based on the presence of dysplastic nevi or melanoma or both in members of the patient's family. We report on the cytogenetic study of three nevi in a young patient with a family history of melanoma. Each nevus showed a simple clonal chromosome change. The t(6;15)(q13;q21) translocation found in one of them seems of particular significance in view of the fact that a similar one, with breakpoint at 6q13 was reported both in an acquired nevus from a patient with a family history of melanoma and in a case of cutaneous metastatic melanoma. These observations seem to support the hypothesis of the existence of a biological continuum between normal melanocyte and melanoma. Furthermore, the finding of chromosome changes similar to those associated with melanoma reinforces the need for a careful follow-up of patients with dysplastic nevi.

Tumor progression, early diagnosis and prognosis of melanoma

Primary melanomas evolve from melanocytes or from precursor lesions through two stages: the radial and vertical growth phases. The radial growth phase may be in situ or microinvasive, but is a non-tumorigenic neoplastic process, while the vertical growth phase is tumorigenic. The prognosis in radial growth phase is excellent irrespective of thickness or other variables. Curable radial growth phase melanomas can be recognized by surveillance of patients identified by screening for risk markers which include dysplastic nevi, common nevi, freckles, and other indicators of chronic or acute sun exposure or sun sensitivity. The prognosis in vertical growth phase depends on attributes of the tumor and of the host. The tumor mitotic rate, the presence of host tumor-infiltrating lymphocytes (TIL) within the vertical growth phase, and tumor thickness are the most powerful predictors of survival. New prognostic attributes are needed not only to provide for more accurate prognosis and diagnosis, but also to test the relevance of in vitro or animal studies in a human neoplastic system. Such attributes will be developed in the future based on markers that are associated with tumor progression. Candidate markers include growth factors and cytokines and their receptors, adhesion molecules and their ligands, chemotactic and motility factors, immune response-related molecules, and tumor-associated proteases. Some of these markers that are represented in the transition from radial to vertical growth phase will be reviewed. The tumor progression model presented here has been of value in the development of more accurate prognostic models, and in the elucidation of mechanisms of the malignant phenotype in melanoma.

Risk of cutaneous malignant melanoma in patients with nonfamilial atypical nevi from a pigmented lesions clinic

BACKGROUND

Atypical nevi (AN) are regarded as a major risk factor for occurrence of malignant melanoma. Few studies report an increase in relative risk for melanoma in patients with nonfamilial AN.

OBJECTIVE

We measured the risk of melanoma in 195 patients with nonfamilial AN.

METHODS

In a retrospective follow-up study the number of newly diagnosed melanomas during follow-up were inventoried. Included patients were invited for skin screening and nevus count.

RESULTS

On the basis of our calculations, the relative risk for invasive melanoma in patients with nonfamilial AN, including those patients with a history of melanoma, is 41. For individuals with AN without a previously diagnosed melanoma, the relative risk was 37. Multivariate analysis did not reveal a specific risk factor for the occurrence of melanoma (including number of AN) because of small numbers. Invasive melanomas occurred in persons having 1, 5, 12, and 172 AN, respectively.

CONCLUSION

An increased risk for invasive cutaneous malignant melanoma in patients with nonfamilial AN was established.

Conjunctival melanoma

Conjunctival melanoma is an uncommon tumor that is likely to recur and carries an overall mortality rate of approximately 30%. The seemingly unpredictable and enigmatic character of this entity has initiated much debate over the past decades regarding the etiology, histogenesis, prognosis, and preferred management. This review outlines the historical perspective; incidence and demographics; etiologic factors; histogenesis; cytogenetic findings; clinical characteristics; histopathologic and ultrastructural features; differential diagnoses; classifications; management of primary, recurrent, and systemic disease; survival after conjunctival melanoma; and diverse factors of potential prognostic significance. Finally, a brief outlook on present and future research objectives is provided.

Lower Frequency of Sister Chromatid Exchanges and Altered Frequency of HLA B-region Alleles among Individuals with Sporadic Dysplastic Nevi

Sister chromatid exchanges (SCE) were analyzed in peripheral blood lymphocytes of 24 individuals, following diagnosis, and prior to surgical removal, of a sporadic dysplastic nevus (DN). Lower SCE values and variability were found in 23 sporadic DN individuals compared with controls (2.52+0.12 and 3.76±0.22 SCE/cell, respectively). These DN individuals, contrarily to healthy controls and some types of tumor patients whose cells are hypersensitive to mutagenic agents, did not show increased SCE rates as a consequence of cigarette smoking, alcohol consumption and diagnostic radiation treatments. These observations are in contrast with clinical evidence that similar lesions are both markers or risk and precursors of malignancy in individuals with multiple nevi, affected by the dysplastic nevus syndrome (DNS) or belonging to FMM (familial malignant melanoma) families. Three HLA class I alleles out of 72 tested were found more frequently in sporadic DN individuals compared with controls: B37 (p<0.05), B52 (p<0.01) and B70 (p<0.01). Whether the greater chromosomal stability (as shown by the SCE analysis), and/or the altered frequency of some HLA alleles could influence the chance of developing cutaneous malignancy in DN individuals is yet to be evaluated.

Malignant melanoma from the dermatologic perspective

Early recognition and treatment of thin cutaneous melanomas (stages Ia and Ib) have contributed to a decreased case-fatality rate during the past several decades. The only known preventable risk factor for melanoma is sun protection in childhood, which directly affects the number of melanocytic nevi developing in an adult. Additional risk factors, clinical features, and the malignant potential of precursor lesions are discussed. The four major clinicopathologic subtypes of melanoma are described with recommendations for appropriate biopsy techniques for suspected melanoma. Nationwide skin cancer screenings by dermatologists and greater public awareness of the warning signs of melanoma have enhanced detection of early melanoma and have promoted chances for a cure.

Posterior uveal melanoma. The Swedish perspective

Posterior uveal melanoma is the most common primary intraocular malignant tumour and in Sweden some 70-80 new cases present each year. While uveal melanoma is more prevalent in the setting of ocular melanocytosis and neurofibromatosis, there is little conclusive data on the aetiology. Most patients experience a progressive visual field defect and present with a grey or greyish-brown mass of the posterior choroid. Diagnostic procedures include fluorescein angiography, ultrasound and magnetic resonance imaging. In some cases, intraocular biopsy may be required to make a correct diagnosis. Posterior uveal melanomas can usually be managed by any of a number of eye-preserving options like plaque radiotherapy and charged particle irradiation, but eyes containing large tumours are often enucleated. Nearly half of patients with posterior uveal melanoma, and in particular those with large tumours, ultimately succumb to metastatic disease. While most patients with tumour dissemination are treated with systemic chemotherapy possibly combined with interferon, metastatic spread confined to the liver may potentially be managed by intraarterial perfusion chemotherapy or liver resection. However, outcome of patients with systemic disease remains extremely poor with a median survival following detectable tumour dissemination of only two to five months. There are still insufficient data on the impact of various treatments on survival, but a large prospective trial addressing this issue is in progress. The present review summarizes the state-of-the-art knowledge and current management of posterior uveal melanoma from a Swedish perspective.

Comet assay demonstrates a higher ultraviolet B sensitivity to DNA damage in dysplastic nevus cells than in common melanocytic nevus cells and foreskin melanocytes

We used the single cell gel electrophoresis assay (comet assay) to study ultraviolet B (UVB)-induced DNA damage in pigment cells. This assay detects DNA damage, mainly DNA strand breaks and alkali labile sites in the DNA molecule. We studied the effect of biologically relevant doses (comparable to 2-3 MED (minimal erythemal dose) for in vivo irradiated full-thickness skin) of monochromatic UVB light of 302 nm on cultured melanocytes derived from foreskin, common melanocytic nevi, and dysplastic nevi. We were able to demonstrate a linear dose-response relationship between UV dose and the migration coefficient of the comet tail in all three types of pigment cells. Nevus cells originating from dysplastic nevi showed the highest sensitivity to UVB irradiation: 65% higher induction of DNA damage compared to the induction in foreskin melanocytes. Common melanocytic nevus cells were most resistant and showed a 30% lower induction of DNA damage in comparison to foreskin melanocytes. Differences in chromatin structure and cell cycle profile may influence the results of the comet assay. Control experiments with x-ray irradiation, which is well known to produce direct DNA strand breaks via radical formation, revealed only small differences between the three types of melanocytic cells. It is unlikely, therefore, that intrinsic nuclear characteristics may account for the observed differences.

Common dermatoses. Part II

Skin diseases are an essential part of primary care medicine. Most dermatologic care is delivered in an outpatient setting. The initial evaluation is usually performed by the primary care physician. Women account for nearly 60% of all visits for dermatologic complaints.

The epidemiology of skin cancer

BACKGROUND

The incidence of skin cancer is increasing at an alarming rate.

OBJECTIVE

To discuss current epidemiologic data concerning the incidence, morbidity, environmental influences, predisposing, host conditions, precursor lesions, and prevention of melanoma and nonmelanoma (basal and squamous cell) skin cancer.

METHODS

The current literature was reviewed in order to provide current epidemiologic data for melanoma, basal cell carcinoma (BCC), and squamous cell carcinoma (SCC).

RESULTS

Skin cancer is exceedingly common and the incidence is rising rapidly. Although the mortality rate for nonmelanoma skin cancer (NMSC) is decreasing, that of melanoma is increasing. Both NMSC and melanoma are associated with significant morbidity. Whereas chronic sun exposure is the main cause of NMSC, the development of melanoma appears to be related to intense, intermittent sun exposure. Ozone depletion has contributed to rising incidence rates of both NMSC and melanoma. In contrast to NMSC, there is not a direct relationship between ultraviolet radiation and melanoma. Genetic susceptibility significantly increases the lifetime risk of acquiring melanoma. There is no precursor lesion for BCC. Precursor lesions for invasive SCC include actinic keratoses and SCC in situ. Melanoma may arise from benign nevi and dysplastic nevi. Prevention of melanoma and NMSC is extremely important since prognosis improves with early detection. Prevention may be achieved by educating patients and physicians how to detect skin cancers early and by decreasing or eliminating exposure to ultraviolet light.

CONCLUSION

The incidence of skin cancer has reached epidemic proportions. Only through heroic efforts by health care professionals and the general public to prevent the development or progression of skin cancer will this epidemic be abated.

Prevalence of primary acquired melanosis and nevi of the conjunctiva and uvea in the dysplastic nevus syndrome. A case-control study

PURPOSE

To investigate whether conjunctival and uveal nevi and primary acquired melanosis are more common in individuals with the dysplastic nevus syndrome than in control subjects derived from the general population.

METHODS

Power calculations were used to determine the sample size. After invitation, 162 individuals with the dysplastic nevus syndrome and 119 control subjects, matched for sex and age but otherwise randomized from the Stockholm county census file, were entered into the study. All individuals were examined in a masked fashion by the same ophthalmologist, and the presence of conjunctival and uveal melanocytic lesions and the iris color, skin type, and hair color of each individual were recorded. Contingency tables and odds ratios were used for statistical evaluation.

RESULTS

The proportions of individuals with the dysplastic nevus syndrome featuring primary acquired melanosis of the conjunctiva, or nevi of the iris and choroid were not significantly different from those of control subjects. However, individuals with the dysplastic nevus syndrome appeared to have a more sun-sensitive skin type and a reddish or blond hair color more often than control subjects.

CONCLUSION

In contrast to previous reports, this study suggests that ocular melanocytic lesions are no more common in individuals with the dysplastic nevus syndrome than in the general population. Therefore, this work does not provide support that periodic ophthalmic surveillance of individuals with the dysplastic nevus syndrome for the purpose of detecting conjunctival or uveal melanomas, or their precursors, is meaningful.

Family study of atypical nevi with investigation of heparin sulfate proteoglycan

BACKGROUND

The epidemiology of atypical nevi (AN) is currently obscure; however the diagnosis must be made early in order to follow these individuals and treat any melanomas that may arise at an early stage, thus preventing premature death.

MATERIALS AND METHODS

Following the guidelines of the NIH on clinical and histologic features of ANS, 38 adult members in 8 families were investigated. Twenty-seven were physically examined and 25 biopsied. Biopsies from ANS and junctional nevi from unrelated persons were also stained with antibodies against heparan sulfate proteoglycan (HSPG).

RESULTS

At least 21 of 38 members had ANS. Staining with HSPG antibodies did not differentiate between ANS and benign junctional nevi, all showing slightly irregular staining. In seven of eight families, two or more family members were affected by ANS.

CONCLUSIONS

Although it is not known whether or not HSPG plays a role in melanomas becoming invasive, or the potential of melanoma developing in ANS there were no differentiating features of staining in ANS, and junctional nevi to help in the differential-diagnosis of the two.

Uveal melanoma and familial atypical mole and melanoma (FAM-M) syndrome

We conducted this study to determine whether occurrence of primary uveal melanoma in the setting of familial atypical mole and melanoma (F A M-M) syndrome (an autosomal dominant cutaneous preneoplastic syndrome) follows a pattern of a hereditary cancer predisposition syndrome. A retrospective review of 4600 consecutive patients with primary uveal melanoma revealed eight patients with biopsy-proven F A M-M syndrome. The clinical profile of these patients was studied and their kindreds analyzed. In patients with F A M-M syndrome, the uveal melanoma occurred at a relatively young age (mean 40 years; range 10-52 years). The diagnosis of F A M-M syndrome preceded or followed the diagnosis of uveal melanoma by as much as 10 years. None of the patients had an associated nonmelanocytic malignancy. Three of the eight patients had a positive family history of melanoma (cutaneous melanoma (2) and uveal melanoma (1). The authors conclude that the occurrence of primary uveal melanoma in the setting of F A M-M syndrome does not follow a clear pattern of a hereditary cancer predisposition syndrome.

DNA repair synthesis following irradiation with 254-nm and 312-nm ultraviolet light is not diminished in fibroblasts from patients with dysplastic nevus syndrome

The DNA excision repair capacity of 23 primary fibroblast lines from patients with dysplastic nevus syndrome was investigated and DNA repair synthesis ("unscheduled DNA synthesis") was determined after UV exposure. Seventeen fibroblast lines from normal donors served as controls. The dose/response experiments included up to ten dose levels and two wavelength ranges: UV-C (using a low-pressure mercury lamp emitting predominantly 254-nm light) and UV-B (artificial "sunlamp" radiation centering around 312-nm light). For each dose level, silver grains over fibroblast nuclei were counted by visual inspection. Twelve cell lines were also evaluated for both UV wavelength ranges using a new semi-automatic image analyzing system. This system included components for rapid sequential identification of both fibroblast nuclei and silver grains sited above them. Silver grains over 100 nuclei were determined for each UV dose level. Dose/response curves were established and analyzed by linear regression. As a quantitative term for assessing DNA excision repair capacity of a cell line we calculated the linear increase (G0) in the number of grains per nucleus, when the UV dose was multiplied by the factor e (i.e. 2.72). The sensitivity of grain detection and resolution of overlapping grains was approximately threefold better in visual than in automatic counting, especially when there were more than 70 grains over nuclei. The time required for visual counting, however, was tenfold that of automatic counting. The variance-weighted mean G0v.w of all fibroblast lines from patients with dysplastic nevus syndrome was found to be 79.1 (+/- 1.8- grains/nucleus, that of fibroblast lines from normal donors was 74.2 (+/- 1.7) grains/nucleus. This difference revealed a slightly better repair capability for cell lines from patients but was at the borderline of detection and, therefore, should not be overinterpreted. From the experimental accuracy achieved by determination of the variance-weighted means of the two groups, we would have been able to detect a difference of 7 and more grains [> 2 x (sigma normal+sigma patients)]. The variance-weighted mean G0v.w of all fibroblast lines from patients with dysplastic nevus syndrome was found to be 76.4 (+/- 1.4) grains/nucleus, whereas that of fibroblast lines from normal donors was only 66.6 (+/- 1.8) grains/nucleus. This difference was statistically significant and, contrary to expectation, revealed better, not worse post-UV DNA repair capability in cell lines from patients that in those from normal donors.(ABSTRACT TRUNCATED AT 400 WORDS)

Atypical mole syndrome: risk factor for cutaneous malignant melanoma and implications for management

The incidence of malignant melanoma is increasing faster than that of any other cancer. It is important to identify subsets of the population at high risk of its development so that they can be observed more closely to identify early melanomas when they are curable. It has been reported worldwide that persons with the atypical mole (dysplastic nevus) syndrome are such a subset at increased risk. A risk gradient for the development of melanoma exists and varies from persons with one or two atypical moles and no family history of melanoma at one end of the spectrum to persons with the familial atypical multiple-mole melanoma syndrome at the other. Guidelines for the management of atypical mole syndrome are presented.

Risk of developing cutaneous malignant melanoma in atypical-mole syndrome: New York University experience and literature review

The presence of atypical moles (AM) is considered to be a marker for an increased risk of developing cutaneous malignant melanoma (MM). The extent to which individuals with the atypical-mole syndrome (AMS) are at risk for developing MM is unknown. We present a review of the world literature and of our experience at New York University. We conclude that the presence of AMS in Caucasians significantly increases the risk of developing MM, regardless of geographic location. A further increase in MM risk is noted if there is a personal and/or family history of MM.

Role of beta 1 integrins in cell spreading and migration of human nevomelanocytes and dysplastic nevi cells on collagen type IV and laminin

We characterized beta 1 integrin subunit expression on three different cultures of benign human nevomelanocytes (NMC) and on four different cell cultures of human dysplastic nevus (DN) cells by flow cytometry analysis and examined their role in mediating cell spreading and migration on collagen type IV (CN IV) and laminin (LN) coated substrates by using a quantitative video image analysis system. The seven human NMC and DNC cultures expressed heterogeneous levels of beta 1, alpha 2, alpha 3 and alpha 6 integrin subunits. Image analysis showed that a significant increase (P < 0.001) in cell spreading and migration of the DN cells was induced on increasing coating concentrations of CN IV and LN. However, the NMC did not show an increase in cell spreading or migration on these substrates when compared to the substrates coated with denatured BSA only. The CN IV-induced cell spreading of the DN cells was significantly inhibited by anti-beta 1 mAb (AIIB2), anti-alpha 2 mAb (P1E6), or anti-alpha 3 mAb (P1B5), but not by mAb against alpha 6 integrin subunit (GoH3). The DN cell spreading on LN was not significantly inhibited by these mAbs. In contrast, the migration of the DN on CN IV and LN was significantly inhibited by anti-beta 1 mAb, anti-alpha 2 mAb, anti-alpha 3 mAb and anti-alpha 6 mAb. These data suggest that the alpha 2 and alpha 3 subunit are important for cell spreading of the DN on CN IV, although they are less important in cell spreading on the extracellular matrix component LN.(ABSTRACT TRUNCATED AT 250 WORDS)

A potential laboratory test for dysplastic nevus syndrome: ultraviolet hypermutability of a shuttle vector plasmid

The diagnosis of the melanoma-prone disorder dysplastic nevus syndrome (DNS) is based currently on a combination of clinical and histopathologic examinations of patients. To develop a potential laboratory test for DNS, we utilized the observation that an ultraviolet light (UV)-treated mutagenesis plasmid shuttle vector has an abnormally increased frequency of mutations after transfection into lymphoblastoid cells from a patient with familial DNS. pSP189 (containing the bacterial suppressor tRNA gene supF as a marker for mutations and a gene for ampicillin resistance for selection) was treated with UV and transfected into familial DNS, xeroderma pigmentosum complementation group A (XP-A), and normal lymphoblastoid cells by electroporation or diethylaminoethyl (DEAE) dextran. Untreated plasmid pZ189K (containing a gene for kanamycin resistance) was co-transfected as an internal standard to reduce the variability of plasmid survival measurements. After 2 d, plasmids were extracted, used to transform an indicator strain of Escherichia coli, and assayed on plates containing ampicillin or kanamycin. Counting light blue or white colonies (containing mutated supF in the plasmid) and blue colonies (with wild type supF) permitted measurement of the plasmid survival and mutation frequency. Transfection by electroporation or DEAE dextran resulted in abnormally reduced survival of UV-treated plasmid after passage through the XP-A but normal survival in the three DNS lines. Transfection of UV-treated plasmid by DEAE dextran yielded a greater hypermutability with the familial DNS lines than by electroporation. These results suggest that pSP189 UV hypermutability with normal UV survival using DEAE dextran transfection may form the basis of a potential laboratory assay for familial DNS.

The histological spectrum of acquired nevi. An analysis of the intraepidermal melanocytic proliferation in common and dysplastic nevi

The histological intraepidermal characteristics considered to be specific to dysplastic nevi (radial extension, lentiginous and disordered nest proliferations, cytological atypia or dyskaryosis) were investigated in a series of 114 acquired nevi showing various clinical appearances in an attempt to establish whether dysplastic nevi can be considered a homogeneous class of lesions, clearly distinct from common nevi. On the basis of the distribution of investigated architectural features, found singly or variously associated, the examined lesions were divided into 5 groups, showing an increasing incidence of dyskaryosis. Results suggest that acquired nevi, rather than two distinct classes (common and dysplastic nevi), form a histological spectrum of lesions, within which the border between lesions implying and not implying an increased melanoma risk cannot be objectively fixed.

UV induction of cyclobutane thymine dimers in the DNA of cultured melanocytes from foreskin, common melanocytic nevi and dysplastic nevi

We compared the induction of cyclobutane thymine dimers after exposure to 302 nm UV in foreskin-derived melanocytes and melanocytes from nevocellular nevi, as well as in melanocytes cultured from dysplastic nevi, precursor lesions of melanoma, derived from four, three and four individuals, respectively. Cyclobutane thymine dimers were quantified in situ by means of an immunofluorescence assay with a specific monoclonal antibody. A method was developed to compare separately performed experiments in a standardized manner. For melanocytes from each source, we demonstrated a linear relationship between UV dose and immunofluorescence. In nevocellular and dysplastic nevi, two subpopulations could be detected, distinguished by their nuclear size. Large nucleated nevocellular nevus cells were most susceptible to the induction of thymine dimers (49% higher induction compared to induction in foreskin melanocytes), while in normal-sized nuclei of these nevus cells the same induction of thymine dimers was found as in nuclei from foreskin melanocytes. In contrast, large nucleated dysplastic nevus melanocytes did not differ from the foreskin melanocytes, while normal-sized nuclei of dysplastic nevus cells showed a lower induction (32% lower induction than in foreskin melanocytes).

Follow-up recommendations for patients with stage I malignant melanoma

The objective of follow-up examinations of patients who have had Stage I invasive malignant melanoma is the early detection of local recurrences, metastases, and new primary melanomas. Model schedules for follow-up intervals were developed based on a survey of eight physicians. These melanoma experts agree that regular follow-up examinations are indicated and that the time intervals between examination vary according to the thicknesses of the melanomas. The patient follow-up schedule derived is: for melanomas up to 0.75-mm thick, every 6 months for years 1 and 2, and annually for years 3, 4, and 5; for melanomas 0.76-1.50 mm thick, every 3 months for years 1 and 2, semi-annually for years 3, 4, and 5; and for melanomas > 1.50 mm thick, every 3 months for years 1, 2, and 3, and semi-annually for years 4 and 5. After the fifth year, the recommendation is to examine all patients annually for life because of the continued risk for recurrences and new primary melanomas. For those individuals at especially high risk for developing multiple primary melanomas more frequent examinations may be appropriate.