Precursors Of Melanoma Research Articles

STAT3 as a Biomarker of Progression in Atypical Nevi of Patients with Melanoma: Dose–Response Effects of Systemic IFNα Therapy

STAT3 as a Biomarker of Progression in Atypical Nevi of Patients with Melanoma: Dose–Response Effects of Systemic IFNα Therapy

Short German guidelines: Malignant melanoma

Malignant melanoma is a malignant tu-mor which arises from melanocytic cellsand primarily involves the skin. For thebalance of these guidelines, the termsmalignant melanoma and melanoma willbe used interchangeably, because thereare no benign melanomas. Melanomascan also arise in the eye (conjunctiva anduvea), meninges and on various mucosalsurfaces. While melanomas are usuallyheavily pigmented, there are also amela-notic tumors. Even small tumors have atendency towards metastasis and thus arelatively unfavorable prognosis. Melan-omas account for 90% of the deaths as-sociated with cutaneous tumors. The incidence of melanoma is increasingworldwide in white populations, especi-ally where fair-skinned peoples receiveexcessive sun exposure. In central Europethe incidence is 10 – 12 / 100,000yearly; in the USA, 10-25 / 100,000yearly; and in Australia the highest inci-dence, 50-60 / 100,000 yearly. In indivi-duals with more pigmentation (Asians,Africans) melanomas are uncommonand almost always found on either acralor mucosal surface. Individuals withlarge numbers of melanocytic nevi andthose with melanoma precursors (dyspla-stic nevi, congenital nevi) are at greaterrisk. The inheritance of melanoma is po-lygenic; 5-10% of melanomas appear inmelanoma-prone families. In addition tothese genetic and constitutional factors,the most important exogenous factor isexposure to UV irradiation. The relativeroles of toxic substances, medicationsand hormones (pregnancy, oral contra-ceptives) are controversial. The immunestatus of the patient plays a major role indetermining the course of melanoma, asnumerous examples of spontaneous re-gression or of rapid progression in im-munosuppressed individuals bear testi-mony.A number of different types of melano-mas can be identified clinically and hi-stologically. Some tumors either repre-sent mixed forms or are not classifiable.Examples of special forms are amelanoticmelanomas, mucosal melanomas, andother extracutaneous melanomas, whichtogether account for about 5% of allmelanomas.

Histologic Spectrum of Melanocytic Nevi Removed from Patients > 60 Years of Age

The histology of melanocytic nevi removed from older patients often differs from that of nevi from younger adults. According to the literature, the most common nevus in older individuals is the intradermal nevus, and purely junctional nevi are rare and should alert the pathologist to a possible melanoma precursor. To evaluate the histologic features of melanocytic nevi removed from patients > 60 year of age. Biopsies of nevi (N=215) from 172 patients > 60 years (mean age 69+/-7 years) were examined retrospectively by three dermatopathologists, a consensus diagnosis was rendered, and the spectrum of histologic features was documented. Junctional melanocytic nevi were frequently diagnosed in older patients (21% of cases) and a lentiginous, often heavily pigmented growth pattern was common (12% of nevi). Severely atypical (dysplastic) changes were found in 6% of nevi removed from older patients. We conclude that benign junctional nevi are relatively common in older patients and that a lentiginous, heavily pigmented growth pattern, traditionally associated with younger individuals, is often seen in both junctional and compound nevi in this older age group. This pattern must be differentiated from dysplastic nevus and melanoma in situ, which they may clinically resemble.

The Significance of Ki-67 Proliferative Index and Cyclin D1 Expression of Dysplastic Nevi in the Biologic Spectrum of Melanocytic Lesions

Familial acquired dysplastic nevi carry a risk for the development of melanoma. However, the results in various studies regarding the significance of sporadic dysplastic nevi as a precursor of malignant melanoma (MM), are controversial. The aim of this study is to investigate cyclin D1 expression and Ki67 proliferative index in a group of melanocytic lesions to address the biologic significance of sporadic dysplastic nevi in the progression of melanocytic lesions. Formalin-fixed paraffin-embedded material from 21 common melanocytic nevi, 42 dysplastic nevi, and 17 primary cutaneous MMs were examined. Standard streptavidin-biotin immunoperoxidase method was used for immunostaining with cyclin D1 and Ki-67 antibody. Nuclear cyclin D1 immunostaining was scored and Ki-67 proliferative index was calculated. Cyclin D1 expression was significantly higher in melanoma than those in other lesions. However, there was no significant difference between dysplastic nevi and common melanocytic nevi in terms of cyclin D1 expression. Ki-67 index was significantly higher in dysplastic nevi compared with common melanocytic nevi and to melanoma compared with dysplastic nevi. There was a significant positive correlation between cyclin D1 expression and Ki-67 proliferative index for each group. The present study indicates significant differences in cyclin D1 expressions and Ki-67 indices among melanocytic lesions. We think that dysplastic nevi are biologically separate from common melanocytic nevi in terms of proliferative activity. Additionally, our results suggest that cyclin D1 expression may be related to malignant phenotype and is associated with high proliferation rate in MM.

Melanoma arising in a hairy nevus spilus

Cutaneous melanoma may develop de novo on normal skin or in contiguity with a potential melanocytic precursor. We report a 45-year-old man who presented with a recently developed nodule in a previously stable congenital nevus. Physical examination revealed a 10x18-cm lesion with speckled lentiginous pigmentation and terminal hairs on the lower back. A 2x2-cm suspicious nodule in the lesion was noted by the patient 2 months earlier. Histopathological evaluation of the nevus and the suspicious nodule revealed the characteristics of a melanocytic nevus and melanoma, respectively. It was interesting for the authors to observe terminal hairs in a lesion that was clinically 'speckled lentiginous' in appearance. This case report is a reminder that there may be great variation in the clinical appearance of nevus spilus, and thus dermatologists must be aware of these lesions as potential precursors of malignant melanoma.

Regression of Atypical Nevus

BACKGROUND Clark nevi (atypical melanocytic nevi) can be considered as risk markers and potential precursors of melanoma. The authors report on the morphologic changes of an atypical nevus by dermoscopic follow-up examination over a 7-year period. CASE REPORT A 43-year-old man had a brown macule on his back, sized 5 mm, with an irregular shape, clinically and dermoscopically diagnosed as an equivocal melanocytic lesion. Dermoscopically during the initial examination, a predominant reticular pattern with peripheral eccentric hyperpigmentation in the lower portion of the lesion could be seen. After 7 months, the area of peripheral eccentric hyperpigmentation had regressed, and after 4.5 years the atypical pigment network had almost disappeared. After 7 years of follow-up, a diffuse area of hypopigmentation and a residual light brown pigmentation were detectable. The histopathologic diagnosis was consistent with an atypical junctional nevus with regression with features of a Clark nevus. CONCLUSION Based on our observation, even a dermoscopically atypical nevus may undergo regression as documented by long-term dermoscopic follow-up.

Regression of Atypical Nevus: An Anecdotal Dermoscopic Observation

Clark nevi (atypical melanocytic nevi) can be considered as risk markers and potential precursors of melanoma. The authors report on the morphologic changes of an atypical nevus by dermoscopic follow-up examination over a 7-year period. A 43-year-old man had a brown macule on his back, sized 5 mm, with an irregular shape, clinically and dermoscopically diagnosed as an equivocal melanocytic lesion. Dermoscopically during the initial examination, a predominant reticular pattern with peripheral eccentric hyperpigmentation in the lower portion of the lesion could be seen. After 7 months, the area of peripheral eccentric hyperpigmentation had regressed, and after 4.5 years the atypical pigment network had almost disappeared. After 7 years of follow-up, a diffuse area of hypopigmentation and a residual light brown pigmentation were detectable. The histopathologic diagnosis was consistent with an atypical junctional nevus with regression with features of a Clark nevus. Based on our observation, even a dermoscopically atypical nevus may undergo regression as documented by long-term dermoscopic follow-up.

Wilms Tumor 1 Expression Present in Most Melanomas but Nearly Absent in Nevi

Pigmented lesions are common, yet they present diagnostic and therapeutic challenges. They range from nevi, which are clinically stable, to melanomas, which are notorious for distant metastasis and death. Both nevi and melanomas arise from melanocytes, which are neural crest derivatives, and melanocyte precursors migrate from the paraspinal area to their eventual location at the dermoepidermal junction. Atypical nevi have been clinically considered to be precursors of melanoma, and recently, biochemical abnormalities have been found that are present in both nevi and melanomas, including inactivation of the p16INK4a tumor suppressor gene and mutations in B-raf. These mutations suggest not only that nevi and melanomas share a common origin but also that additional events are required for transformation to malignant melanoma. We performed a Panomics protein array comparing a radial growth melanoma cell line with a vertical growth melanoma cell line and found that the transcription factor Wilms tumor 1 is highly expressed in the vertical growth cell line compared with the radial growth cell line. Using immunohistochemical analysis, we compared expression of archival nevi and melanomas in a tissue microarray. We found that Wilms tumor 1 is expressed in most melanomas but is nearly absent in nevi. Immunohistochemical analysis for Wilms tumor 1 may be clinically useful in distinguishing nevi from melanoma.

Esophageal melanocytosis morphologic features and review of the literature.

Endoscopic or macroscopic esophageal melanocytosis is a benign clinicopathologic entity characterized by melanocytic proliferation in esophageal squamous epithelium and melanin deposition in the mucosa. Little is known about the etiology and natural course of this condition, although it has been suggested to be a precursor of primary esophageal melanoma by some authors. Following a search of the bibliographic databases (PubMed and Medline) regarding esophageal melanocytosis and melanosis, thirty-four cases of isolated esophageal melanocytosis (including one unpublished case from us) were found. The histopathologic features of esophageal melanocytosis are reviewed and its differential diagnosis with other pigmented esophageal lesions is discussed.

Esophageal Melanocytosis Morphologic Features and Review of the Literature

Endoscopic or macroscopic esophageal melanocytosis is a benign clinicopathologic entity characterized by melanocytic proliferation in esophageal squamous epithelium and melanin deposition in the mucosa. Little is known about the etiology and natural course of this condition, although it has been suggested to be a precursor of primary esophageal melanoma by some authors. Following a search of the bibliographic databases (PubMed and Medline) regarding esophageal melanocytosis and melanosis, thirty-four cases of isolated esophageal melanocytosis (including one unpublished case from us) were found. The histopathologic features of esophageal melanocytosis are reviewed and its differential diagnosis with other pigmented esophageal lesions is discussed.

Precursors to melanoma and their mimics: nevi of special sites

Melanocytic nevi, which are benign tumors of melanocytes, may have occasional cosmetic significance but, for the most part, they are important only in relation to melanoma. Nevi are the most important simulants of melanoma, both clinically and histologically, and can usually be reliably distinguished from melanomas using published criteria. Some lesions are characterized by greater degrees of atypia and may be more difficult to diagnose. Dysplastic nevi are among the most important simulants of melanoma. Nevi may also be important as potential precursors of melanoma; however, most nevi are stable and will not progress to malignancy. Nevi are vastly more common than melanomas and the rate of progression of individual lesions is very low. Therefore, nevi are not as a rule managed by wholesale excision to prevent melanoma. Nevi are also important as risk markers, identifying individuals at greater risk of developing melanoma in the future. Dysplastic nevi and, to a lesser extent, common acquired and congenital nevi are among the most important melanoma risk markers. Nevi of special sites have been identified as nevi that may show atypical features suggestive of a dysplastic nevus or of a melanoma. However, they are not risk markers and they are not malignancies. Nevi of genital skin, acral skin, and flexural skin are among the most important ‘nevi of special sites'. It is important, in considering the differential diagnosis of a lesion in a special site, to avoid overcalling such a lesion as a melanoma or a dysplastic nevus because this could lead to excessive treatment. Conversely, it is important to avoid undercalling a lesion that is a dysplastic nevus or a melanoma as a nevus of special sites, because in this circumstance a patient could lose the opportunity either for surveillance to recognize a developing melanoma at an early, curable stage, or for definitive treatment of an established malignancy. In this monograph, dysplastic nevi and nevi of special sites are compared and contrasted in relation to melanoma.

Apaf‐1 expression in human cutaneous melanoma progression and in pigmented nevi

Malignant melanoma is notoriously refractive to therapy and resistant to apoptosis. This may reflect the downregulation of Apaf-1, an important mediator of mitochondrial-dependent apoptosis, observed in vitro in melanoma cell lines and by immunohistochemistry for Apaf-1 protein in histological samples of primary and metastatic melanomas. Although it has been suggested that loss of Apaf-1 expression may be an indicator of malignant transformation in melanoma, previous studies on Apaf-1 expression in benign pigmented nevi were performed without reference to their histologic type. Here we have evaluated the expression of Apaf-1 mRNA by fluorescence in situ hybridization and of Apaf-1 protein by immunohistochemistry in a large panel of human melanomas and in eight types of pigmented nevi, considered potential precursors for cutaneous melanoma. We observe a strong negative correlation between melanoma progression assessed according to Clark classification and the expression of Apaf-1. A significant decrease in Apaf-1 expression was observed between Clark II and Clark III lesions, the stages usually associated with a transition from horizontal to vertical growth phase of melanoma. There was also statistically significant difference in Apaf-1 mRNA expression between melanomas of Breslow thickness <1 mm and >4 mm. No Apaf-1 expression could be detected in lymph node melanoma metastases. These results suggest that Apaf-1 expression may become a prognostic marker for progress of human cutaneous melanoma and further support the notion that loss of Apaf-1 may be an important contributory factor in the development of the disease.

Clinical and Dermoscopic Changes in Common Melanocytic Nevi in School Children: The Framingham School Nevus Study

Background: Nevi are potential precursors of malignant melanoma and are important risk factors for the development of the disease. Childhood may be a critical time for the formation and evolution of nevi. Objectives: To document the development of new nevi and to document the clinical and dermoscopic changes in index nevi in school children during a 1-year follow-up. Methods: Digital photographs and dermoscopic images of the back of subjects were compared at baseline and 1-year follow-up to assess changes in nevi counts and in clinical and dermoscopic features of index nevi. Results: Overall participation rate was 81% (42/52). 56.4% of study participants were found to have an increased number of nevi at 1-year follow-up. All nevi were small and clinically insignificant. Fifty percent of study participants were found to have dermoscopic changes in their index nevi at 1-year follow-up. Eighty-five percent of these changes were classified as subtle and 15.0% as obvious. Conclusions: A significant portion of students developed new nevi over the course of 1 year. Most index nevi remained stable in pattern and structure. Benign dermoscopic changes occurred in 50.0% of index nevi. However, none of the dermoscopically changed nevi revealed any major changes and the overall nevus pattern remained unchanged. The relevance of these changes is uncertain and further follow-up may elucidate their significance.

Use of color texture in determining the nature of melanocytic skin lesions—a qualitative and quantitative approach

Melanocytic nevi are recognized as precursors of melanoma. Aiding in early recognition of melanoma, we estimated color texture parameters, fractal dimension and lacunarity of melanoma and other melanocytic nevi. Digital images of the lesions were processed. Graphic three-dimensional pseudoelevation images of the lesions and surrounding skin were produced to identify irregularities in color texture within the lesions. Estimation of lacunarity and fractal dimension followed in order to produce a numerical estimate of the coarseness of color texture. Clinicians readily perceive the resulting “geographical” images. Irregularity in the anaglyph, which might veil malignancy, is effortlessly identified through these images, and therefore an early excision of a suspect lesion is indicated.

The prevalence of interferon-alpha transcription defects in malignant melanoma

The type I interferons, interferon-alpha (IFN-alpha) and interferon-beta (IFN-beta), are situated on the short arm of chromosome 9, specifically 9p21-22. This locus lies very close to an area that is deleted or rearranged in nearly half of all melanomas tested. The identification of 9p rearrangements in both melanoma precursor lesions (dysplastic naevi) and primary lesions has implicated the 9p locus in the early stages of melanoma development. Recent evidence has demonstrated that metastatic melanoma cell lines have a specific loss of IFN-alpha gene expression, a defect that appears to occur at the level of transcription. In this study, we examined the expression of IFN-alpha in cell lines isolated from the various stages of melanoma progression, with a view to determine the prevalence of the IFN-alpha transcription defects exhibited by malignant melanoma, and to assess whether the loss of IFN-alpha expression was particular to a certain stage of melanoma progression. We showed that all the melanoma cell lines tested (n=20) demonstrated an inability to express IFN-alpha, a defect that was reflected in the apparent inactivity of the IFN-alpha promoter. These defects were found to occur in cells isolated from early melanomas, lending support to the hypothesis that IFN-alpha has a role in the aetiology of malignant melanoma.

Interleukin-6 Gene Ablation in a Transgenic Mouse Model of Malignant Skin Melanoma

Interleukin (IL)-6 is a pleiotropic cytokine that has been shown to inhibit the growth of early stage and to promote the proliferation of advanced stage melanoma cells in vitro. In patients with metastasizing melanomas, highly increased IL-6 blood levels correlate with a poor response to chemotherapy and a worse overall prognosis, suggesting that IL-6 promotes melanoma progression in vivo. Here, we analyzed the role of IL-6 in melanoma development and progression in a transgenic mouse model. We bred IL-6-deficient mice with MT-ret transgenic animals predisposed for melanomas. While MT-ret transgenic animals develop severe melanosis of the skin and subcutis and subsequent melanomas at an incidence of 80% during their first year of life, MT-ret mice devoid of IL-6 developed preneoplastic melanosis and consecutive melanomas significantly less frequently (47%; P < 0.05). Moreover, the tumors were significantly smaller in the groups of MT-ret mice lacking one (P < 0.05) or both (P < 0.01) copies of the IL-6 gene. Immunoblot analysis revealed that ret transgene expression was not reduced in the skin of mice lacking IL-6, indicating that the observed decrease of melanoma incidence and of tumor sizes was not because of a down-regulation of transgene expression. Taken together, these results indicate that IL-6 enhances both the development of melanoma precursor lesions and the subsequent growth of the resulting tumors in the MT-ret model of melanoma development.

Análisis morfométrico y contenido de ADN en el nevo displásico. Estudio comparativo frente a otras lesiones melanocíticas benignas

Abstract—Introduction. The «dysplastic nevus» (DN) was described in 1978. This lesion is associated with an increased risk of melanoma, but the significance of DN as a precursor of melanoma is controversial. Numerous researchers have tried to correlate the presence of DN with a specific type of phenotype and genotype that would include the presence of abnormal DNA content. ObjectiveTo compare the DNA content and the nuclear morphometry of DN with that of benign melanocytic lesions. Through an image analysis technique, we sought to measure, in an objective (quantitative) manner, the cytological atypia we observed in a subjective manner in the histological study of the DN. Material and methodsThe nuclear area, shape factor and DNA content of 52 melanocytic lesions were determined: 8 junctional nevi, 10 compound nevi, 10 intradermal nevi, 21 DN and 3 cases of melanoma as a control. The morphometric and cytometric studies were carried out using a CUE-2 (Olympus) image analysis system. ResultsAll of the cases were diploid, with the exception of 2 DN, 2 interdermal nevi and the 3 melanomas. The nuclear shape factor was the best discriminant in differentiating DN from the rest of benign melanocytic lesions, as it was statistically significant. We did not find morphometric differences between familial and/or multiple DN and sporadic ones. ConclusionThe nuclear cytological changes observed in the DN with morphometry generally overlap those seen in the rest of the benign melanocytic lesions studied, except the nuclear shape factor, which is more irregular in the DN.

SAGE Identification and Fluorescence Imaging Analysis of Genes and Transcripts in Melanomas and Precursor Lesions

Melanomas of sporadic and familial origin develop in a stepwise fashion in approximately 40-80% of all cases; yet, the genetic events governing the progression from nevocytic precursor lesions to early and advanced-stage melanomas remain largely unknown. In the present study, we provide an analysis of genes that were identified in four recently generated primary and metastatic melanoma Serial Analysis of Gene Expression (SAGE) libraries. In addition to SAGE tags corresponding to transcripts with unknown function, or to unidentified transcripts, known genes were identified that hitherto have not been shown to be expressed or have a function in early and advanced-stage melanomas and/or melanoma precursor lesions. Conducting fluorescence imaging analysis with cyanine dye-conjugated antibodies and oligonucleotides, we established the expression pattern of ATM, HEI10, PKD1, KAI11, IL-10R, and hypothetical protein FLJ11151 in nevus and melanoma specimens.

Melanoma ex naevo: a study of the associated naevus.

It has been shown that the co-occurrence of melanoma and pre-existing naevus is not a random event and that acquired naevi may be precursors of melanoma. A critical area of chromosomal loss at 9p21 has been implicated in the genesis of malignant melanoma, representing a site of frequent somatic chromosomal deletions in melanoma. Allelic deletions within this chromosomal region most often include the tumour suppressor gene p16. The objective of this study was to search for allelic deletions on chromosome 9p21 in naevus cell clusters. A microdissection-based approach was used to analyse 30 archived primary cutaneous melanomas and associated naevi for loss of heterozygosity (LOH) at 9p21 using the polymorphic DNA markers D9S171 and IFNA. LOH was detected in 10 out of 27 informative naevi (37%) at D9S171 and in eight out of 19 (42%) at IFNA in the dissected naevus cell clusters, and in nine out of 27 (33%) at D9S171 and seven out of 19 (36%) at IFNA in the associated melanomas. In eight out of 46 (17%) cases, LOH was detected simultaneously in the naevus and the associated melanoma using both markers. Our results suggest a causal relationship for the development of melanoma within a pre-existent associated naevus. These data support the hypothesis that lesions within 9p21 play an important role in early melanoma development, since these genetic alterations are found in histologically benign melanoma-associated naevi.

Fluorescence imaging analysis of upstream regulators and downstream targets of STAT3 in melanoma precursor lesions obtained from patients before and after systemic low-dose interferon-alpha treatment.

Atypical nevi are the precursors and risk markers of melanoma. Apart from persistently monitoring these nevocytic lesions and resecting them at the earliest signs of clinical changes, there is as yet no systemic clinical treatment available to interfere with their progression to melanoma. To explore clinical treatments that might interfere with and possibly prevent atypical nevus progression, a previous study documented that 3 months systemic low-dose interferon-alpha (IFN-alpha) treatment of patients with a clinical history of melanoma and numerous atypical nevi, led to inactivation of the STAT1 and STAT3 transcription factors in atypical nevi. Based upon this finding, we initiated a second study to determine whether systemic low-dose IFN-alpha treatment also impairs the expression of upstream regulators and downstream targets of STAT1 and STAT3 in atypical nevi. Using cyanine dye-conjugated antibodies, fluorescence imaging analysis revealed expression of JAK2, JNK1, AKT1, NF-kappa B, and IFN-alpha/beta receptor in benign and atypical nevi, and early- and advanced-stage melanomas. To determine possible changes in the level of expression of these molecules in atypical nevi, excised before and after 3 months of systemic low-dose IFN-alpha treatment, newly designed optical imaging software was used to quantitate the captured fluorescent hybridization signals on a cell-by-cell basis and across an entire nevus section. The results of this analysis did not provide evidence that systemic low-dose IFN-alpha treatment alters the level of expression of upstream regulators or downstream targets of STAT1 and STAT3.