Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “NEVI”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1994

Growth dynamics of acquired melanocytic nevi. Higher reactivity of proliferating cell nuclear antigen in junctional and compound nevi than intradermal nevi.

BACKGROUND: The histogenesis of acquired melanocytic nevi is still a matter of debate. OBJECTIVE: To provide data on the histogenesis, we investigated the lesional area of acquired melanocytic nevi and the proliferative activity of the nevus cells. METHODS: Proliferative activity was examined with a monoclonal antibody against proliferating cell nuclear antigen (PCNA). The lesional area of the nevus was estimated in histologic sections. RESULTS: Intradermal nevus was the largest of the acquired melanocytic nevi but had few PCNA-positive nevus cells. In contrast, junctional nevi were smallest and showed the highest PCNA positivity. Statistical analysis showed a significant inverse correlation between the largest lesional area and PCNA positivity. CONCLUSION: The findings of the present study are in accordance with an epidermal melanocytic origin of acquired melanocytic nevi.

Antigens, Neoplasm↗
PubMed1983

Increased intraepidermal melanocyte frequency and size in dysplastic melanocytic nevi and cutaneous melanoma. A comparative quantitative study of dysplastic melanocytic nevi, superficial spreading melanoma, nevocellular nevi, and solar lentigines.

Dysplastic melanocytic nevi (DMN) are distinguished histologically by a hyperplasia of variably atypical intraepidermal melanocytes in a lentiginous epidermal pattern. In order to further characterize the intraepidermal melanocytes of DMN, 4 representative specimens each of DMN, acquired nevocellular nevi (NCN), solar lentigines (SL), and superficial spreading melanoma (SSM) were selected on the basis of predetermined criteria, confirmed in a blind histologic assessment, and compared in a quantitative morphologic study using 6 micron-thick hematoxylin and eosin stained sections of L-dihydroxyphenylalanine (dopa) preincubated vertical tissue slices of lesion and adjacent normal skin. The average melanocyte frequency, expressed as the percent of dopa-reactive perikarya among 600 consecutive basal unit cells, was significantly greater in DMN (60 +/- 23%) than in NCN (18 +/- 3%), SL (25 +/- 7%), and adjacent skin (14 +/- 3%), but similar to that in SSM (71 +/- 11%). The average mean diameter of 200 consecutive epidermal basal unit melanocytes was significantly larger in DMN (11 +/- 2 microns) than in NCN (7 +/- 0.4 microns), SL (6 +/- 0.1 microns), and adjacent skin (6 +/- 0.4 microns), but significantly smaller than in SSM (16 +/- 3 microns). The observed similarities of intraepidermal melanocytes in selected DMN and SSM, as well as distinct differences from melanocytes in selected NCN and SL, support the hypothesis that some varieties of DMN may represent potential precursors of cutaneous melanoma.

Adult↗
PubMed1995

The eastern Australian childhood nevus study: prevalence of atypical nevi, congenital nevus-like nevi, and other pigmented lesions.

BACKGROUND: Various melanocytic lesions are frequently observed. An understanding of phenotypic factors and environmental stimuli that are associated with these lesions may help explain their pathogenesis. OBJECTIVE: This study was undertaken to determine the prevalence of atypical nevi, blue nevi, cafe-au-lait macules, congenital nevus-like nevi, halo nevi, nevi spili, nevi 5 mm or more in diameter, and skin-colored melanocytic nevi in a population of schoolchildren and to explore risk factors including solar radiation in the development of these melanocytic lesions. METHODS: A cross-sectional study was performed by the same medical investigators to examine schoolchildren in three Australian cities that span a wide range of latitudes. RESULTS: Data from 1123 white Australian schoolchildren, 6 to 15 years of age, were analyzed. Acquired melanocytic nevi (atypical nevi, nevi > or = 5 mm in diameter, and skin-colored nevi) were more likely to develop in older fair-skinned subjects who had freckles and lived closest to the equator. Café-au-lait macules and congenital nevus-like nevi were observed in 36.3% and 4.4% of the total population, respectively. Prevalence for both these types of melanocytic lesions increased significantly with decreasing latitude. Halo nevi were present in 5.3% of the subjects and were usually solitary. These lesions were related to the presence of atypical nevi primarily by virtue of their size rather than of other features of clinical atypia. CONCLUSION: Like melanocytic nevi in general, large and atypical nevi are strongly influenced by geographic location and, by implication, degree of solar radiation. The same can be said for congenital nevus-like nevi, which suggests that many so-called congenital nevi are in fact acquired early in life.

Adolescent↗
PubMed1991

Dysplastic melanocytic nevi contain high levels of pheomelanin: quantitative comparison of pheomelanin/eumelanin levels between normal skin, common nevi, and dysplastic nevi.

The degree and type of melanogenesis, i.e., either eumelanin of pheomelanin, has been shown to be a reliable marker for the differentiation of the melanocyte. If exposed to UV light, these two melanins were reported to behave differently; eumelanin was photoprotective whereas pheomelanin was phototoxic to cultured tumor cells. Our previous study indicated that dysplastic melanocytic nevus (DMN) undergoes altered melanogenesis, forming pheomelanosome-like granules. The present study examined chemically the type and degree of melanin synthesized in 31 melanocytic nevi excised from 27 patients as compared with that occurring in the surrounding normal skin. The tissue content of eumelanin and pheomelanin was expressed by the amounts of pyrrole-2,3,5-tricarboxylic acid (PTCA) and aminohydroxyphenylalanine (AHP), respectively. We found that DMN lesions contain significantly higher amounts of pheomelanin than either common melanocytic nevus (CMN) or normal skin. Differences in pheomelanin content between DMN and CMN could not be accounted for by inherently higher levels of pheomelanin within the skin in general from DMN patients. Our present finding substantiates our previous claim that epidermal melanocytes in DMN undergo deranged melanogenesis.

Adolescent↗
PubMed2001

Dermoscopic classification of atypical melanocytic nevi (Clark nevi).

OBJECTIVES: To create a dermoscopic classification of atypical melanocytic nevi (Clark nevi) and to investigate whether individuals bear a predominant type. DESIGN: Digital dermoscopic images of Clark nevi were classified according to structural features, ie, reticular, globular, or homogeneous patterns or combinations of these types. The nevi were also characterized as central hypopigmented or hyperpigmented, eccentric peripheral hypopigmented or hyperpigmented, or multifocal hypopigmented or hyperpigmented. SETTING: Two pigmented skin lesion clinics. PATIENTS: We examined 829 Clark nevi on 23 individuals. MAIN OUTCOME MEASURE: A reliable dermoscopic classification of Clark nevi and frequency of different dermoscopic types. RESULTS: Using the dermoscopic classification, the 829 Clark nevi were classified as follows: 221 (26.7%) as reticular, 167 (20.1%) as reticular-homogeneous, 148 (17.9%) as globular-homogeneous, 112 (13.5%) as reticular-globular, 89 (10.7%) as homogeneous, 84 (10.1%) as globular, and 8 (1.0%) as unclassified. Most individuals were prone to a predominant type of Clark nevus. Seven individuals (30%) showed a single type of Clark nevus in more than 50% of their nevi and 5 (22%) in more than 40% of their nevi. CONCLUSIONS: The proposed dermoscopic classification of Clark nevi is easily applicable and allows a detailed characterization of the different dermoscopic types of Clark nevi. Knowledge of these dermoscopic types should reduce unnecessary surgery for benign melanocytic lesions. Exact classification of the different types of Clark nevi is a necessary prerequisite for further clinical, dermoscopic, and histopathologic studies, which will give new insights in the biology of acquired melanocytic nevi.

Adolescent↗
PubMed1988

Independence of dysplastic nevi from total nevi in determining risk for nonfamilial melanoma.

In the determination of risk for melanoma, relatively little is known about the possible independence of two important predictors, total nevi and clinically dysplastic nevi. From a study conducted in Sydney, Australia [see J. J. Nordlund et al., Cancer Res. 45, 1855-1861 (1985)], 246 cases of melanoma (excluding 7% of targeted patients with a history of melanoma in a first-degree relative) were compared with 134 nonmelanoma controls. Participants had been examined by a dermatologist and an oncologist. Logistic regression analysis was used and included an age-sex interaction term in computing all estimates of relative risk in this report. Relative risk for melanoma in those with 16+ total nevi was significantly elevated at 1.8 but declined to a statistically nonsignificant level of 1.2 (95% confidence limit (CL): 0.7, 2.0) after adjustment for dysplastic nevi. In contrast, relative risk for melanoma in those with any dysplastic nevi was 7.6 (95% CL: 3.6, 16.0) but was maintained at a similarly elevated and statistically significant level of 7.7 (95% CL: 3.5, 17.1) after adjustment for total nevi. These patterns were even more evident in the younger half of the study population. The analyses suggest that much of the association between TN and nonfamilial melanoma is explained by the presence of dysplastic nevi and, conversely, they imply that dysplastic nevi represent a clinically distinct, qualitative disorder rather than simply a quantitative disorder wherein dysplastic nevi stem merely from an increase in total nevi. The dysplastic nevus syndrome accounts for 32% of all nonfamilial melanomas.

Adult↗
PubMed1998

The augmentation of melanocytic nevi in guinea pigs by solar-simulated light: an animal model for human melanocytic nevi.

Strong epidemiological evidence confirms the role of sunlight in human melanoma induction. Furthermore, the frequency of melanocytic nevi is a good indicator of future development of melanoma and a short-term marker of adverse reactions to melanoma-inducing sun exposure in humans. Thus, the aim of this study was to develop and define an animal model for sunlight-induced nevi that can be used as a surrogate model for sunlight-induced melanoma. Five treatment groups of 30-40 Hartley albino guinea pigs/group were treated with topical 7,12-dimethylbenzanthracene at a dose range of 6-240 mg on the dorsum of the skin. At week 20, half of the animals in each group were given a 12-month regimen of minimal erythemal solar-simulated light, 3 times/week, increased weekly to maintain erythema. These regimes induced epidermally derived pigmented melanocytic nevi clinically and histologically similar to human nevi (junctional, compound, and dermal). S100 and HMB45 staining was also consistent with the patterns seen in human nevi. In contrast to the high-dose 7,12-dimethylbenzanthracene-treated animals (60 and 240 mg), where solar-simulated light had no effect on nevi multiplicity, those groups treated with low doses (24, 12, and 6 mg) had a significant increase in nevi multiplicity after 12 months of solar-simulated light treatment (24 mg, 0.5 nevi/animal unirradiated versus 1.4 nevi/animal irradiated, P = 0.03; 12 mg, 0.2 unirradiated versus 1.2 irradiated, P = 0.02; 6 mg, 0 unirradiated versus 1.9 irradiated, P = 0.008). UVB-induced minimal erythemal dose was unaltered after exposure to photoreactivating light, consistent with the observation of others that placental mammals lack the DNA photolyase responsible for strong photoreactivation seen in nonplacental mammals and lower metazoans. Thus, our guinea pig model has some of the essential elements required to be a robust animal model for human nevi and a surrogate model for melanoma. These nevi are augmented by solar-simulated light, are histologically similar, occupy the same level within the skin, have the same natural history as human nevi, and are produced in an animal lacking strong photoreactivation. These features are not found in any previously described small laboratory animal model.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1991

Correlation of clinical pigmentary characteristics with histopathologically-confirmed dysplastic nevi in nonfamilial melanoma patients. Studies of melanocytic nevi IX.

The dysplastic melanocytic nevus (DMN) is the key clinical marker for the familial dysplastic nevus syndrome and has also been associated with high risk for non-familial melanoma. Characterisations of DMN itself have been qualitative and on a case-by-case basis. In this study, we provided clinical and histological characterisations for each of 150 pigmented lesions from 150 patients with prior malignant melanoma. The steps involved in the study were as follows: (1) The two to four clinicians characterised pigmented lesions on each of 150 patients, and the lesion closest in characteristics to an atypical nevus was quantitatively described based on size, border characteristics and colour characteristics; (2) The lesion was then removed and independently quantified by a single dermatopathologist without knowledge of the clinical features; (3) We computed the correlation between each of the clinical variables and each of the histologic features for each of the 150 patients. Histologic diagnosis of dysplastic nevus was strongly associated with total number of palpable arm nevi, total number of any arm nevi, total number of nevi on the body of any type, and total number of clinically atypical nevi on the body (correlation coefficients 23.2% to 30.4% with P less than 0.01 in each instance). There were also strong correlations between the counts of numbers of nevi and certain types of architectural histologic features, including fusion (bridging of junctional nests), lymphocyte response and fibroplasia of the papillary dermis. Histologic evaluation of solar elastosis was negatively correlated with total numbers of nevi and total number of clinically atypical nevi (P less than 0.01). Freckling on forearm and on shoulders showed no significant positive or negative correlations with any of the histologic features nor with overall diagnosis of dysplastic nevus. We conclude that observations regarding total numbers of nevi (either normal or clinically atypical nevi) are correlated with nuclear and architectural histologic dysplasia on biopsy of the most atypical pigmented lesions.

Adult↗
PubMed2001

Histologic features seen in changing nevi after therapy with an 810 nm pulsed diode laser for hair removal in patients with dysplastic nevi.

BACKGROUND: The majority of lasers used for hair removal target melanin as the chromophore. In contrast with other cutaneous applications of lasers, lasers used for hair removal must generate a limited, controlled degree of thermal damage to permanently remove hairs. AIM: To remove excess back hair from two male patients, one with a history of multiple nevi, and prior biopsies showing features of dysplastic nevi, and the other with large nevi greater than 6 mm in diameter and a family history of malignant melanoma. METHODS: Both patients received monthly treatments with an 810 nm, pulsed, high-power diode laser using a fluence of 20 J/cm2 and 25-30 J/cm2, respectively, and a pulse duration of 30 ms. RESULTS: Both patients presented 1 month after their last treatment with changing nevi within the treatment areas. Neither patient had clinical inflammation or other alterations suggestive of change in the nevi related to treatment. Thus, the nevi were excised with no mention of the previous laser treatment. The histologic features in all nevi were similar. There was subepidermal blister formation with elongation and disruption of nevus cells. There was homogenization of the collagen within the papillary dermis in all lesions. Only small foci of nevus cells could be identified in the dermis in some of the biopsy specimens. In these biopsy specimens, the dermal stromal matrix homogenization extended into the reticular dermis. CONCLUSIONS: Laser targeting of nevus cells and surrounding structures may produce clinically atypical nevi in areas previously treated for hair removal. This should be kept in mind, especially in patients with a history of dysplastic nevi or with a personal or family history of malignant melanoma.

Adult↗
PubMed1993

Nevi, other than dysplastic and Spitz nevi.

Cutaneous nevi are common lesions that develop by proliferation of melanocyte-derived cells. The majority develop as junction nevi from melanocytes at the epidermo-dermal junction. Cells from this proliferation pass into the underlying dermis forming compound nevi. Later junctional melanocytic activity ceases, leaving an intradermal nevus. A minority of nevi, mainly blue nevi, arise from intradermal melanocytes. Histological variants of melanocytic nevi exist and can be the source of difficult diagnostic problems. Nevi are important as clinical and histological simulators of cutaneous melanoma, as precursor lesions for melanoma (although the actual chance of malignant transformation of an individual nevus is low) and as cosmetic problems (mainly large congenital nevi). Cutaneous nevi are to be separated clinically and histologically from melanomas that are comprised of nevocyte-like cells (minimal deviation melanoma).

Adult↗
PubMed2004

Number of satellite nevi as a correlate for neurocutaneous melanocytosis in patients with large congenital melanocytic nevi.

BACKGROUND: Patients with large congenital melanocytic nevi (LCMN) are at risk for neurocutaneous melanocytosis (NCM). Patients with LCMN on the posterior axis or in conjunction with many satellite melanocytic nevi seem to represent subgroups at greatest risk. OBJECTIVE: To determine the relationship between LCMN location, number of satellite nevi, and risk of NCM. DESIGN: Descriptive survey study. SETTING: An Internet Web-based registry of patients with LCMN, maintained by a nevus support group (Nevus Outreach Inc). PARTICIPANTS: Individuals with LCMN or their guardians visiting the Nevus Outreach Web site were provided the opportunity to complete the questionnaire. OUTCOME MEASURES: Location of LCMN, number of satellite nevi, and NCM as assessed by patient self-report. RESULTS: A total of 379 patients with LCMN were evaluated, 26 of whom had NCM. A significantly higher percentage of patients with NCM had their LCMN on the posterior axis compared with patients without NCM (96% and 70%, respectively). Patients with NCM had significantly more satellite melanocytic nevi compared with non-NCM patients (median, 68.5 and 18, respectively). Furthermore, patients with LCMN and more than 20 satellites had a 5.1-fold (95% confidence interval, 1.9-14.0) increased risk for NCM compared with LCMN patients with 20 or fewer satellites. Logistic regression analysis, controlling for age, sex, number of satellite nevi, and LCMN location, identified number of satellite nevi as the only significant risk factor for NCM. CONCLUSIONS: The presence of large numbers of satellite nevi is the most important risk factor for NCM in patients with LCMN. Although location of the LCMN on the posterior axis was a moderate risk factor for NCM in univariate analysis, the strength of the relationship was attenuated in the multivariate analysis.

Child↗
PubMed2003

The influence of painful sunburns and lifetime sun exposure on the risk of actinic keratoses, seborrheic warts, melanocytic nevi, atypical nevi, and skin cancer.

Painful sunburns are implicated in the pathogenesis of squamous cell carcinoma, basal cell carcinoma, and malignant melanoma. Chronic exposure to ultraviolet radiation is known as the most important risk factor for the development of actinic keratoses and squamous cell carcinoma. The purpose of the study was to assess the effect of painful sunburns and lifetime sun exposure on the development of actinic keratoses and seborrheic warts in relation to the development of squamous cell carcinoma and basal cell carcinoma, and on the development of melanocytic nevi and atypical nevi in relation to the development of malignant melanoma. We made use of a cohort of 966 individuals who participated in a case-control study to investigate environmental and genetic risk factors for skin cancer. Exposure measurements for sunlight were collected and actinic keratoses, seborrheic warts, melanocytic nevi, and atypical nevi were counted. Relative risks were estimated using exposure odds ratios from cross-tabulation. Multivariate logistic regression was used to adjust for potential confounders. The recall of painful sunburns before the age of 20 y was associated with an increased risk of squamous cell carcinoma, nodular basal cell carcinoma, and multifocal superficial basal cell carcinoma as well as actinic keratoses. Odds ratios with 95% confidence intervals adjusted for age, sex, and skin type were 1.5 (0.97; 2.3); 1.6 (1.1; 2.2); 2.6 (1.7; 3.8); and 1.9 (1.4; 2.6) for the three types of nonmelanoma skin cancer and actinic keratoses, respectively. Painful sunburns before the age of 20 y were also associated with an increased risk of malignant melanoma and the development of its precursors, melanocytic nevi and atypical nevi. Odds ratios with 95% confidence intervals adjusted for age, sex, and skin type were 1.4 (0.86; 2.1); 1.5 (1.1; 2.0); and 1.4 (0.88; 2.3) for malignant melanoma and the two types of precursors, respectively. Lifetime sun exposure was predominantly associated with an increased risk of squamous cell carcinoma (p-value for trend=0.03) and actinic keratoses (p-value for trend <0.0001) and to a lesser degree with the two types of basal cell carcinoma. By contrast, lifetime sun exposure appeared to be associated with a lower risk of malignant melanoma, despite the fact that lifetime sun exposure did not diminish the number of melanocytic nevi or atypical nevi. Neither painful sunburns nor lifetime sun exposure were associated with an increased risk of seborrheic warts.

Adult↗
PubMed1994

Melanocytic nevi in children. II. Observer variation in counting nevi.

A survey of benign melanocytic nevi was conducted among children in Perth, Western Australia, in 1985. Children were examined by one of a team of five nurses who counted all of their nevi. Linear regression was performed on the logarithmically transformed mole counts to assess the degree of interobserver variation. Among 2,354 white children aged 5-14 years, 3.9% of the variation in numbers of nevi of all sizes and 7.7% of the variation in nevi 2 mm or more in diameter was attributed to variation among observers. The observer variation was less for the back than for any other body site. Differences between observers were greater in children with heavy freckling than in children with little or no freckling. However, the interaction between degree of freckling and observer accounted for more than 1% of the variation in counts only at sites where freckling was common (the face and neck and the upper limbs). The reproducibility of counts made by pairs of observers on 236 of the children, estimated by intraclass correlation coefficients, was 0.79 for all nevi and 0.65 for nevi 2 mm or more in diameter. The mean count of nevi on the back obtained by examining photographs of 100 children aged 8-9 years (11.9 nevi) was similar to that recorded by the examiners (12.3; p = 0.31), and the two measures were highly correlated (r = 0.89).

Adolescent↗
PubMed2004

Nodal melanocytic nevi in sentinel lymph nodes. Correlation with melanoma-associated cutaneous nevi.

Melanocytic nevi occurring in lymph nodes create diagnostic difficulty by mimicking metastases. Few studies describe nodal nevi in sentinel lymph nodes (SLNs) excised for melanoma. We evaluated 72 cases in which patients had undergone SLN biopsy for melanoma. Lymph nodes and cutaneous melanomas were evaluated according to a standard protocol. Nodal nevi were identified in 8 patients (11%). Of these, 6 (75%) had an associated cutaneous nevus (P = .006). Of 21 patients with an associated nevus, 4 (19%) with nodal nevi had a cutaneous nevus with congenital features (P = .01). The incidence of nodal nevus correlated with a Breslow thickness greater than 2.5 mm (P = .02). Nevi were not seen in non-SLNs. Nodal nevi appear more frequently in patients with melanoma-associated cutaneous nevi, particularly if congenital features are present. The increased frequency of nodal nevi in SLNs relative to non-SLNs suggests an etiology of mechanical transport of nevus cells.

Adolescent↗
PubMed1997

Classification of melanocytic nevi: do nodular and flat nevi develop differently?

Previous classifications of melanocytic nevi have not been generally accepted for various reasons. The classification by Ackerman and Magana-Garcia (Am J Dermatopathol 1990;12:193) has also been subject to criticism, even though it is the first taking into account of both clinical and histological aspects of these tumors. To reproduce the findings by Ackerman and Magana-Garcia, the following findings were observed: (a) cases with features of two different types were occasionally seen--33 of 185 cases (17.3%) of nevi of Miescher's and Unna's type showed features of both types and 6 of 205 (3%) flat nevi had a slight to pronounced papillomatous surface--(b) contrary to Unna's theory of "Abtropfung," no junctional nevi of Unna's and Miescher's type and no dermal nevi of cases with a flat configuration were seen. It is concluded that the main differences among melanocytic nevi were seen between flat and nodular nevi, showing (a) different clinical configurations (b) different histological features, (c) possibly a different histogenesis, and (d) different malignant potentials.

Humans↗
PubMed1999

Promising therapy for congenital giant pigmented nevi using acellular autograft nevi-dermal matrix.

As promising new therapy for congenital giant pigmented nevi, the authors investigated the potential use of an acellular autograft nevi-dermal matrix in combination with a split-thickness skin graft. To address whether the processed acellular nevi-dermal matrix from frozen skin could be reconstituted as a viable dermal base, the authors grafted it onto full-thickness skin defects in nude rats. Fibroblast infiltration and neovascularization into the acellular nevi-dermal matrix were observed. However, because the disappearance of the residual melanotic granules of the grafted dermis took 16 weeks, the authors excised with scissors the superficial layer of the acellular nevi-dermal matrix containing a large quantity of melanin. The appearance after using this method was relatively superior even compared with the full-thickness skin graft. The success of their experimental animal model using the acellular nevi-dermal matrix covered with split-thickness skin grafts confirms the potential value for the clinical application of this treatment for congenital giant nevi.

Animals↗
PubMed1994

Associated factors in the prevalence of more than 50 common melanocytic nevi, atypical melanocytic nevi, and actinic lentigines: multicenter case-control study of the Central Malignant Melanoma Registry of the German Dermatological Society.

Several case-control studies identified common and atypical melanocytic nevi as major risk indicators for the development of cutaneous melanoma. The present investigation was planned to detect factors associated with the prevalence of these melanoma risk markers. Whole-body examination findings and interview data of 513 melanoma patients and 498 age- and sex-matched control subjects were analyzed. Existence of more than 50 common melanocytic nevi and the presence of atypical melanocytic nevi were significantly related to age and gender, with significantly elevated relative risk for their prevalence before the age of 60 and in males. Additionally, sunburns before the age of 20 were significantly associated with both more than 50 common melanocytic nevi (relative risk = 1.7) and the presence of atypical melanocytic nevi (relative risk = 1.5). Actinic lentigines were found more frequently with increasing age, and the presence of actinic lentigines was significantly related to a tendency of freckling in adolescence (relative risk = 2.0) and to two or more sunburns after the age of 20 (relative risk = 1.6). In conclusion, sunburns before the age of 20 contribute to the development of multiple melanocytic nevi and atypical melanocytic nevi. In adulthood, this type of sun exposure is associated with the development of actinic lentigines. The relative risk of developing cutaneous melanoma increases in association with the development of these benign melanocytic lesions.

Adolescent↗