Heritability and gene-environment interactions for melanocytic nevus density examined in a U.K. adolescent twin study

Risk factors for melanoma include environmental (particularly ultraviolet exposure) and genetic factors. In rare families, susceptibility to melanoma is determined by high penetrance mutations in the genes CDKN2A or CDK4, with more common, less penetrant genes also postulated. A further, potent risk factor for melanoma is the presence of large numbers of melanocytic nevi so that genes controlling nevus phenotype could be such melanoma susceptibility genes. A large Australian study involving twins aged 12 y of predominantly U.K. ancestry showed strong evidence for genetic influence on nevus number and density. We carried out essentially the same study in the U.K. to gain insight into gene-environment interactions for nevi. One hundred and three monozygous (MZ) and 118 dizygous (DZ) twin pairs aged 10-18 y were examined in Yorkshire and Surrey, U.K. Nevus counts were, on average, higher in boys (mean = 98.6) than girls (83.8) (p = 0.009) and higher in Australia (110.4) than in the U.K. (79.2, adjusted to age 12 y, p < 0.0001), and nevus densities were higher on sun-exposed sites (92 per m(2)) than sun-protected sites (58 per m(2)) (p < 0.0001). Correlations in sex and age adjusted nevus density were higher in MZ pairs (0.94, 95% CI 0.92-0.96) than in DZ pairs (0.61, 95%CI 0.49-0.72), were notably similar to those of the Australian study (MZ = 0.94, DZ = 0.60), and were consistent with high heritability (65% in the U.K., 68% in Australia). We conclude that emergence of nevi in adolescents is under strong genetic control, whereas environmental exposures affect the mean number of nevi.

Rhabdomyosarcoma in a congenital pigmented nevus

A 7-month-old boy had a giant pigmented lesion involving the trunk and thighs that exhibited many hyperpigmented hairy and verrucous nevi. One of the nevi ulcerated and on histological examination consisted of pleomorphic rhabdomyosarcoma cells that stained for muscle-specific actin (HHF-35), desmin, and myoglobin. Around the tumor, in the dermis, benign pigmented nevus cells were observed. The occurrence of malignant tumors, other than malignant melanoma, in pigmented nevi is rarely described.

Clinicopathological features of eyelid skin tumors. A retrospective study of 5504 cases and review of literature.

Eyelid tumors are the most common neoplasm in daily ophthalmology practice and encompass a wide variety of benign and malignant tumors. In this retrospective study, we report the clinical and histological features of 5504 eyelid skin tumors diagnosed at the Laboratory of Ophthalmopathology of the Hôpital Ophtalmique Jules Gonin, Lausanne, Switzerland, between January 1989 and December 2007. Benign tumors largely predominated over malignant ones, representing 84% of cases in this series, and the 5 most frequent subtypes were squamous cell papilloma (26%), seborrheic keratosis (21%), melanocytic nevus (20%), hidrocystoma (8%), and xanthoma/xanthelasma (6%). Basal cell carcinoma was the most frequent malignant tumor (86%), followed by squamous cell carcinoma (7%) and sebaceous carcinoma (3%). For several tumor subtypes, there was a poor correlation between clinical and histological diagnosis, stressing the numerous pitfalls in the diagnosis of eyelid tumors. We further discuss our results with reference to previously published series.

Resultados del tratamiento de nevos melanocíticos con láser

Introducción A pesar de que los nevos melanocíticos son un motivo de consulta frecuente en nuestra población no existen estudios a nivel de Colombia acerca de su tratamiento, a nivel mundial existe muy poca literatura al respecto por lo que hay un vacío conceptual en este campo. Objetivos Evaluar los cambios en cuanto a la presencia de pigmento y cicatrización, en los nevos melanocíticos adquiridos tratados con láser, basados en la experiencia de un solo centro en Bogotá. Materiales y métodos Es un estudio observacional de antes y después, en una cohorte histórica, de 90 casos de nevos melanocíticos adquiridos, tratados con láser en Uniláser Medica, en los que se evaluó la presencia de pigmento, cicatrización, y otras variables, con un control realizado a no menos de 3 meses de la intervención. Resultados Se encontró un rango de edad entre los 18 -51 años, promedio 27,59 años; fototipo de III-V; en el 32% de los casos, solo fue requerida una sesión de láser de Co2 y Erbio, para el aclaramiento completo de la misma. La duración del eritema en el 54,4% los casos fue de 1 a 3 meses. En un 64,4% quedó pigmento residual al control, pero de éstos casos el 48,2% fue entre un 5 a un 10% del inicial. El 58,9% hizo cicatriz, de éstos el 63% fue estética. La satisfacción por parte de los pacientes es alta a pesar de la persistencia pigmentaria y/o la presencia de cicatriz. Discusión El tratamiento de nevos melanocíticos adquiridos con láser es una opción terapéutica que genera cambios estadísticamente significativos en cuanto a pigmento, cicatriz estética y alta satisfacción por parte de los pacientes. Se requieren estudios, analíticos, para determinar eficacia del tratamiento.

Role of ROC1 protein in the control of cyclin D1 protein expression in skin melanomas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Clinical, dermoscopic and histopathological evaluation of the Meyerson nevus - Case report

Meyerson nevi occur whenever a rare focal and transitory eczematous eruption arises around melanocytic lesions. The same phenomenon has also been observed in non-melanocytic lesions as well. Herein we report the case of a 25 year old, male patient, who had noticed, two months before, the arising of a pruriginous and erithematous halo around two nevi localized on his abdomen. The lesions were found to be atypical on dermoscopic examination and he was submitted to surgical excision of both nevi. Histopathological examination revealed displastic compound melanocytic nevi, surrounded by intraepidermical vesicles and spongiosis. Present report suggests that Meyerson phenomenon does not seem to alter dermoscopic features of nevi.

Increased Melanocytic Nevi in Patients with Inherited Ichthyoses: Report of a Previously Undescribed Association

Ichthyosis is a heterogeneous cornification disorder. Melanocytic lesions have not been previously described in association with ichthyosis. Their clinical importance lies in the fact that they may simulate melanoma clinically and dermoscopically, as seen in epidermolysis bullosa. The objective of this study was to evaluate the clinical, dermoscopic, and histopathologic features of nevi and lentigines in 16 patients with autosomal recessive congenital ichthyosis-lamellar ichthyosis and non-bullous ichthyosiform congenital erythroderma. Patients underwent general clinical examination dermoscopy. The more suspicious lesions were excised and to histopathologic examination. Most patients (n = 13) reported no personal or familial history of melanoma or atypical nevi. All of the patients had at least five atypical melanocytic lesions. Ten of the 16 patients had at least one atypical nevus or lentigo. This study suggests that increased atypical melanocytic nevi may be a feature of long-standing congenital ichthyoses. Whether this finding is disease-related or a coincidental observation is difficult to ascertain. As an unequivocal discrimination from malignant melanoma in vivo is not always possible, regular clinical follow-up of patients with ichthyosis and increased or unusual nevi is recommended.

Linkage and Association Analysis of Radiation Damage Repair Genes XRCC3 and XRCC5 with Nevus Density in Adolescent Twins

Previous studies have shown that a deficiency in DNA damage repair is associated with increased cancer risk, and exposure to UV radiation is a major risk factor for the development of malignant melanoma. High density of common nevi (moles) is a major risk factor for cutaneous melanoma. A nevus may result from a mutation in a single UV-exposed melanocyte which failed to repair DNA damage in one or more critical genes. XRCC3 and XRCC5 may have an effect on nevus count through their function as components of DNA repair processes that may be involved directly or indirectly in the repair of DNA damage due to UV radiation. This study aims to test the hypothesis that the frequency of flat or raised moles is associated with polymorphism at or near these DNA repair genes, and that certain alleles are associated with less efficient DNA repair, and greater nevus density. Twins were recruited from schools in south eastern Queensland and were examined close to their 12th birthday. Nurses examined each individual and counted all moles on the entire body surface. A 10cM genome scan of 274 families (642 individuals) was performed and microsatellite polymorphisms in XRCC3 and adjacent to XRCC5 were also typed. Linkage and association of nevus count to these loci were tested simultaneously using a structural-equation modeling approach implemented in MX. There is weak evidence for linkage of XRCC5 to a QTL influencing raised mole count, and also weak association. There is also weak evidence for association between flat mole count and XRCC3. No tests were significant after correction for testing multiple alleles, nor were any of the tests for total association significant. If variation in XRCC3 or XRCC5 influences UV sensitivity, and indirectly affects nevus density, then the effects are small.

Indicators for the total number of melanocytic naevi : an adjunct for screening campaigns. Observational study on 292 patients.

BACKGROUND: The presence of multiple melanocytic naevi is a strong risk factor for melanoma. Use of the whole body naevus count to identify at-risk patients is impractical. OBJECTIVES: To (i) identify a valid anatomical predictor of total naevus count; (ii) determine the number of naevi that most accurately predict total naevus count above 25, 50 and 100; and (iii) evaluate determinants of multiple melanocytic naevi and atypical naevi. METHODS: Clinical data from 292 consecutive Spanish patients consulting for skin lesions requiring debriding were collected throughout 2009 and 2010. Correlations between site-specific and whole body naevus counts were analysed. Cut-offs to predict total naevus counts were determined using the area under the receiver operating characteristic curve. RESULTS: The studied population was young (median age 31 years, interquartile range 28-43). The naevus count on the right arm correlated best with the total nevus count (R(2) 0·80 for men, 0·86 for women). Presence of at least five naevi on the right arm was the strongest determinant of a total naevus count above 50 [odds ratio (OR) 34·4, 95% confidence interval (CI) 13·9-85·0] and of having at least one atypical naevus (OR 5·7, 95% CI 2·4-13·5). Cut-off values of 6, 8 and 11 naevi on the right arm best predicted total naevus count above 25, 50 and 100, respectively. CONCLUSIONS: Our results support the arm as a practical and reliable site to estimate the total naevus count when screening or phenotyping large populations. Threshold values for the number of naevi on the arm are proposed to help identify patients for melanoma screening.

Epidermal Growth Factor Gene (EGF) Polymorphism and Risk of Melanocytic Neoplasiay

A common single nucleotide polymorphism (SNP) in the 5' untranslated region (5'UTR) of the epidermal growth factor (EGF) gene modulates the level of transcription of this gene and hence is associated with serum levels of EGF. This variant may be associated with melanoma risk, but conflicting findings have been reported. An Australian melanoma case-control sample was typed for the EGF+61A>G transversion (rs4444903). The sample comprised 753 melanoma cases from 738 families stratified by family history of melanoma and 2387 controls from 645 unselected twin families. Ancestry of the cases and controls was recorded, and the twins had undergone skin examination to assess total body nevus count, degree of freckling and pigmentation phenotype. SNP genotyping was carried out via primer extension followed by matrix-assisted laser desorption time of flight (MALDI-TOF) mass spectroscopy. The EGIF+61 SNP was not found to be significantly associated with melanoma status or with development of nevi or freckles. Among melanoma cases, however, G homozygotes had thicker tumors (p=0.05), in keeping with two previous studies. The EGF polymorphism does not appear to predispose to melanoma or nevus development, but its significant association with tumor thickness implies that it may be a useful marker of prognosis.

Melanoma in adolescents: A case-control study of risk factors in Queensland, Australia

The incidence of melanoma increases markedly in the second decade of life but almost nothing is known of the causes of melanoma in this age group. We report on the first population-based case-control study of risk factors for melanoma in adolescents (15-19 years). Data were collected through personal interviews with cases, controls and parents. A single examiner conducted full-body nevus counts and blood samples were collected from cases for analysis of the CDKN2A melanoma predisposition gene. A total of 201 (80%) of the 250 adolescents with melanoma diagnosed between 1987 and 1994 and registered with the Queensland Cancer Registry and 205 (79%) of 258 age-, gender- and location-matched controls who were contacted agreed to participate. The strongest risk factor associated with melanoma in adolescents in a multivariate model was the presence of more than 100 nevi 2 mm or more in diameter (odds ratio [OR] = 46.5, 95% confidence interval [Cl] = 11.4-190.8). Other risk factors were red hair (OR = 5.4, 95%Cl = 1.0-28.4); blue eyes (OR = 4.5, 95%Cl = 1.5- 13.6); inability to tan after prolonged sun exposure (OR = 4.7, 95%Cl = 0.9-24.6); heavy facial freckling (OR = 3.2, 95% Cl = 0.9-12.3); and family history of melanoma (OR = 4.0, 95%Cl = 0.8-18.9). Only 2 of 147 cases tested had germline variants or mutations in CDKN2A. There was no association with sunscreen use overall, however, never/rare use of sunscreen at home under the age of 5 years was associated with increased risk (OR = 2.2, 95%Cl = 0.7-7.1). There was no difference between cases and controls in cumulative sun exposure in this high-exposure environment. Factors indicating genetic susceptibility to melanoma, in particular, the propensity to develop nevi and freckles, red hair, blue eyes, inability to tan and a family history of the disease are the primary determinants of melanoma among adolescents in this high solar radiation environment. Lack of association with reported sun exposure is consistent with the high genetic susceptibility in this group. (C) 2002 Wiley-Liss, Inc.