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Small and intermediate congenital melanocytic nevi have a lifetime risk of developing melanoma estimated to range from 0% to 5%. Secondary benign melanocytic proliferations commonly arise in congenital melanocytic nevi; however, some are difficult to definitively distinguish from malignant melanoma based on clinical features and conventional histology. Herein, we describe the use of comparative genomic hybridization in supporting the diagnosis of a deep penetrating nevus developing within a congenital melanocytic nevus of a 3-month-old infant.

Turner's syndrome (TS) is a genetic disorder caused by numeric and/or structural abnormalities of the X chromosome; it is characterized by short stature, gonadal dysgenesis, and frequently by webbed neck, cubitus valgus, and lymphedema at birth. TS has been associated with several cutaneous abnormalities including an increased frequency of pigmented nevi, but few reports consider nevi in detail. Halo nevus (HN) is clinically defined as a melanocytic nevus surrounded by a halo of depigmentation. Vitiligo, a dermatologic disorder characterized by the presence of depigmented patches on the skin, has been described in the list of cutaneous findings associated with TS. The aim of this study was to determine the prevalence of HN and vitiligo in TS and to evaluate if a correlation between major histocompatibility complex genes, karyotype, autoimmunity, therapies, and the presence of HN exists. Of the 72 patients with TS examined, 13 had HN, a prevalence of 18.05%, which was significantly higher than in our control group (1%; P=.000001). On the contrary, only 2 patients with TS (2.77%, P=not significant) had vitiligo. By comparing the distribution of HLA class I alleles between patients with TS who did (13 of 72) and did not (59 of 72) have HN, we observed a significantly higher frequency of HLA-Cw6 in patients with TS and HN than in those without HN (26.92% vs 6.78%, respectively; P=.0067; odds ratio=5.06). The study of HLA class II genomic polymorphisms showed that the DRB1(*)0701 and DQB1*02 alleles for patients with TS and HN were overrepresented when compared with those without HN (34.61% vs 11.86%, respectively, P=.0078, odds ratio=3.93; and 34.61% vs 19.49%, respectively, P=.1386, odds ratio=2.19). In conclusion, this study is the first to demonstrate an increased prevalence of HN for patients with TS. Furthermore, the data suggest that a HN putative susceptibility gene in TS is located close to the HLA-C locus.

Eruptive nevi have been reported after renal allograft transplantation, particularly in children and adolescents, and immunosuppression has been suggested to favor both benign and malignant melanocyte proliferation. In this study, we describe the dermoscopic features of eruptive melanocytic nevi in 10 children, adolescents, and young adults with renal allografts in whom multiple melanocytic nevi developed during a short period after transplantation. Dermoscopy of the eruptive pigmented lesions revealed a peripheral rim of brown globules. This rim of peripheral globules was present in 80% of the patients with eruptive nevi and in most of the lesions of the same patient. The other standard dermoscopic criteria for melanocytic nevi were normal. In our study, we confirm previous reports concerning the development of eruptive nevi in children and adolescents receiving immunosuppressive therapies. In particular, we showed by dermoscopy the presence of a characteristic symmetrical rim of peripheral brown globules. This finding is consistent with the hypothesis that a symmetrical peripheral rim of globules may indicate rapid enlargement of melanocytic lesions. Moreover, we have identified a new group of patients characterized by this dermoscopic feature. These patients are children, adolescents, and young adults with renal allografts receiving immunosuppressive therapy and it is plausible that this dermoscopic characteristic may be found in eruptive nevi developed in association with immunosuppression from any cause.

Background: Although melanocytic nevi are the strongest known risk factors for melanoma, their etiology is not well understood., Objectives: This study was performed to assess the roles of constitutional pigmentary factors and sun exposure in the development of new nevi in adolescents., Methods: A cohort of 111 school children, aged 12 and 13 years at baseline, were followed up for 5 years. Whole-body counts of nevi of all sizes and detailed sun exposure histories were updated each year. Analyses of full-body nevus counts and of nevus counts on the face and neck region and on the shoulder and back region were undertaken by means of log-linear regression, allowing for repeated measures., Results: Mean whole-body nevus counts were 130.1 (SD = 69.9) in 1990 and 215.5 (SD = 127.1) in 1994. Shoulder and back counts were consistently higher than face and neck counts. Subjects with heavy shoulder freckling had increased nevus counts on all sites investigated, with a means ratio for whole-body counts of 1.11 (95% CI, 1.03-1.19), compared with those with no freckling. Those who spent all of their school lunch times in the midday sun had a means ratio of 1.62 (95% CI, 1.15-2.29) compared with those who spent very little time in the sun during the lunch period. Summer holiday sun exposure was not significantly associated with development of nevi in this adolescent cohort., Conclusion: The degree of freckling, especially on the shoulders, and habitual midday sun exposure, rather than holiday sun exposure, are significant determinants of melanocytic nevi in Queensland adolescents.

Background: Several syndromes in which melanocytic nevi and scoliosis were present in the same patient have been described. No control study has been made to date to determine whether there is a relationship between these disorders., Objective: We attempted to demonstrate the association between acquired melanocytic nevi (AMN) and idiopathic scoliosis (IS)., Methods: We studied 93 patients with IS, aged 10 to 18 years, from our hospital. Controls were randomly selected from 2 schools; Adam's forward bending test was used to exclude persons with clinical scoliosis, and the control group finally comprised 101 pupils. An observational, cross-sectional study was done. All AMN 2 mm or larger observed on the body were counted by one dermatologist. Other variables reported as risk factors in the number of nevi were also considered. Reliability of AMN counts was previously demonstrated., Results: The median number of AMN was 18 (range, 10-42) in the IS group and 8 (range, 3-13) in controls (P <.001). The persons with scoliosis had more non-AMN dermatologic lesions than the controls (P <.05). Light phenotype correlated with many AMN. On multivariate analysis only scoliosis and age accounted independently for the number of AMN., Conclusion: IS is associated with many AMN. Multiple AMN may become a diagnostic marker for IS, and these two malformations might constitute a syndromic association.

Widespread melanocytic nevi may rarely appear suddenly after a severe bullous disease. We describe two patients in whom eruptive melanocytic nevi developed 3 weeks after a severe episode of Stevens-Johnson syndrome. Benign melanocytic proliferation may develop after a bullous dermatosis and should not be confused with malignant or metastatic melanoma.

Background: It is not known why melanocytic nevi (MN) become dysmorphic (atypical) in patients with the atypical mole syndrome (AMS). A complex origin for acquired MN has been postulated. Genetic predisposition, solar radiation, and/or the formation of a sun-induced circulating mitogenic factor may contribute to the formation of MN., Objective: This study was undertaken to help elucidate the pathogenesis of atypical MN in patients with AMS., Methods: The number of common and atypical MN was determined for a defined sun-protected area on the buttocks in 150 patients with AMS (cases) and 150 control subjects without AMS. Patients and control subjects were matched for age and sex and were classified into risk groups for the development of malignant melanoma according to the Rigel classification., Results: MN on the buttocks were found in 23% of patients with AMS and 9% of control subjects (p < 0.003). In patients versus control subjects the mean number (1.3 vs 1.2, respectively) and mean diameter (5.7 vs 5.9 mm, respectively) of MN on the buttocks did not differ significantly. The MN in both patients and control subjects were not atypical clinically. The odds ratio for having AMS if MN were present on the buttocks was calculated to be 1.56 (95% confidence interval, 1.25 to 1.95)., Conclusion: Although the patients were 2.6 times more likely to have MN on their buttocks than the control subjects, clinically the MN did not differ significantly in number or appearance from those found on the buttocks of control subjects. It is hypothesized that the formation of some atypical MN requires direct solar radiation for their phenotypic expression.

Background: Most epidemiologic studies on risk factors for cutaneous melanoma have been performed in predominantly fair-skinned populations., Objective: Our purpose was to assess by means of a case-control study the importance of common melanocytic nevi (CMN) and clinically atypical nevi (CAN) as risk factors for cutaneous melanoma in a Mediterranean population., Methods: One hundred six patients with invasive cutaneous melanoma and 109 population control subjects were included in the study. All subjects were younger than 70 years of age and were residents of the Florence area., Results: The adjusted odds ratios obtained by exact conditional analysis, accounting for age, sex, place of birth, and residence, were 2.6 (95 confidence interval [CI], 1.0 to 6.7) for 10 to 30 CMN, and 22.3 (CI, 4.8 to 215) for more than 30 CMN (chi 2 for trend, 25.41; p < 0.001), 2.9 (CI, 1.2 to 7.5) for large nevi, and 8.4 (CI, 2.2 to 31.4) for CAN. Tendency to freckle resulted in a twofold increase in risk (odds ratio, 2.2) (CI, 1.0 to 5.2). The relative risk associated with a large number of CMN was statistically significant after adjustment for all other variables. When adjusted for the number of CMN, none of the other variables showed a statistically significant increased risk., Conclusion: A large number of CMN represents the most important risk factor for cutaneous melanoma in the Italian population. The presence of large nevi and CAN did not result in an increased risk when the number of CMN was considered.

Background: Renal allograft transplantation is associated with an increased incidence of malignant melanoma. The development of excess melanocytic nevi may be an indicator of this risk., Objective: This study determines the prevalence of melanocytic nevi in children who have received renal allografts., Methods: Total and regional melanocytic nevi counts were made in 38 children (27 boys, 11 girls) with a renal allograft and in 38 individually age- and sex-matched healthy controls; counts were related to age, sex, skin type, and duration of immunosuppression., Results: There was a significant increase in the total number of nevi in the renal transplant group compared with the control group (p < 0.05), with most marked increases occurring on the back and at acral sites. A strong positive correlation between nevi count and duration of immunosuppression independent of age was observed (p < 0.005)., Conclusion: Excess numbers of melanocytic nevi occur in children with renal allografts. These patients constitute a risk group for malignant melanoma and require continued assessment.

The prevalence of benign pigmented nevi in a group of 187 children, aged 8 or 9 years, was determined for each of 31 anatomic sites. Information on possible associated factors was obtained from the children's parents with a standard interview questionnaire. Pale skin color was found to be associated with a higher prevalence of nevi. A comparison of these data with recent data from Australia supports the hypotheses that (1) the number of nevi is a risk factor for melanoma and (2) groups at high risk of melanoma may be formed in childhood.

Becker's nevus is an uncommon, unilateral, hyperpigmented, hairy cutaneous hamartoma which usually begins in adolescence. Its clinical features and its occurrence mainly in male individuals suggest that androgen stimulation may play a role in its pathogenesis. Androgen receptor assays were performed in a 16-year-old patient with a Becker's nevus. The patient coincidentally had acanthosis nigricans. Lesional tissue showed an androgen receptor level of 634.1 fm/mg protein. A specimen from the contralateral left pectoral area showed no dectectable androgen receptor activity (less than 2.0 fm/mg protein). These results suggest that exquisite androgen sensitivity and stimulation may explain the clinical manifestations of Becker's nevus.

Primary melanoma of the skin, once a rare tumor, has been increasing so rapidly in the past few decades that melanoma now has a higher incidence than Hodgkin's disease. The early diagnosis and surgical treatment of melanoma are the only approach to date that has increased survival--chemotherapy, immunotherapy, and radiation therapy provide little or no benefit. Therefore, all physicians need to be on the alert for early melanoma. This guide is intended to provide the physician both with the tools to diagnose cutaneous melanoma and a suggested approach to its management. It is hoped that as this type of information becomes more widely disseminated, a continued improvement in early recognition and survival will be effected.

A patient with erythema multiforme developed many nevocytic nevi, including a large cluster of such lesions at the sites of healed blisters. The development of eruptive nevocytic nevi in this pattern suggests that cutaneous injury plays a role in their pathogenesis.