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PubMed2005

Spitz nevi and atypical Spitz nevi/tumors: a histologic and immunohistochemical analysis.

A subset of Spitz nevi poses substantial diagnostic difficulty, even among experts, due to its resemblance to malignant melanoma. These lesions are termed atypical Spitz nevi/tumors and there is currently a lack of objective criteria for predicting their biologic behavior. We compared the expression of Ki-67, p21, and fatty acid synthase by immunohistochemistry in 10 atypical Spitz nevi, 28 typical Spitz nevi, 19 compound melanocytic nevi and 18 invasive malignant melanomas. There was a progressive increase in fatty acid synthase cytoplasmic expression with statistically significant differences observed between Spitz nevi and atypical Spitz nevi (P=0.003) and between atypical Spitz nevi and malignant melanoma (P<0.050). Ki-67 nuclear staining was lower in both typical and atypical forms of Spitz lesions than in malignant melanoma (P<0.001). The degree of P21 nuclear expression in atypical Spitz nevi was not significantly different than in Spitz nevi, but was significantly greater than expression in conventional nevi and approached significance after multiple comparisons corrections for malignant melanoma. Thus, a high level of P21 expression makes a tumor more likely to be a typical or atypical Spitz nevus than a malignant melanoma, especially when coupled with a low Ki-67 index and weak expression of fatty acid synthase. These immunohistochemical observations support the concept that atypical Spitz nevi are distinct lesions of borderline biologic behavior residing between Spitz nevi and malignant melanoma. The study also compared a large array of histologic features of 16 cases of typical Spitz nevi in children with 12 typical Spitz nevi in adults. The adult lesions were significantly more likely to be intradermal and to display dermal fibroplasia, but were histologically similar to their pediatric counterparts in all other respects.

Adolescent↗
PubMed2002

Evolution of melanocytic nevi on the faces and necks of adolescents: a 4 y longitudinal study.

All melanocytic nevi on the faces and necks of a cohort of students, initially aged 12-14 y, were mapped and photographed annually for 4 y. The features of each nevus were charted yearly noting changes in size and profile, and the appearance or disappearance of any nevi on a student's face and neck was recorded. Nevi were classified by size (small, < 2 mm; medium, 2-5 mm; large, > 5 mm), and by profile (flat, raised). Data from 20 adolescents selected randomly from the cohort for detailed analysis showed males had about twice as many nevi as females, but there was little difference between sexes in their patterns of nevus development. Approximately half the nevi were small in all years; under 5% were large. Over the 4 y of follow-up the proportion of flat nevi dropped from 70% to 57%, whereas nevus numbers increased by 47% in year 1, with smaller increases in older students. Most new or disappearing nevi were small and flat, although both incident and disappearing nevi could be larger and/or raised. Of the existing nevi that altered in the follow-up period, the tendency was towards an increase in size among raised but not among flat nevi; a lowering of profile among small nevi; and a raising of profile among larger nevi; but there were many exceptions to this pattern. Among several host factors examined, inability to tan after sun exposure was found to be significantly negatively associated with the propensity of nevi to change size over the study period. Overall our findings indicate that, contrary to conventional belief, there is a measurable turnover among melanocytic nevi even in early life.

Adolescent↗
PubMedDate not supplied

Dysplastic nevi of the scalp and forehead in children.

To determine if there is a significant difference in the relative frequency and degree of atypia of sporadic dysplastic nevi from the scalp, face, and neck area in children as compared with nevi from the rest of the body, we reviewed 99 consecutive biopsy specimens of melanocytic nevi from the scalp, face, and neck areas in children less than 18 years of age and compared them with 95 consecutive cases of nevi from other areas of the body in children of the same age. Large numbers of the nevi biopsied from the scalp (13 of 31; 41.93%) and forehead (2 of 10; 20%) were dysplastic. The number of dysplastic nevi from the neck (1 of 58; 1.72%) was not assessed as very different from the incidence found in other regions of the body, where 7 dysplastic nevi (7.36%) from a total of 95 nevi were found. Of the 13 dysplastic nevi from the scalp, 9 showed minimal atypia and 4 showed moderate atypia. No nevi with severe atypia were found. Many pigmented nevi from the scalp and forehead in children in this study were dysplastic. This finding points out the importance of examining the scalp of children for the presence of dysplastic nevi. The majority of nevi from the neck were common nevi.

Adolescent↗
PubMed2002

How good are parents at assessing melanocytic nevi on their children? A study comparing parental counts, dermatologist counts, and counts obtained from photographs.

The objective of this study was to evaluate agreement among counts of melanocytic nevi made by parents, counts made by a dermatologist, and counts made by assessment of photographs. In 1990, 421 schoolchildren aged 6-15 years from Townsville, Queensland, Australia (latitude 19.16 degrees S), participated in the Eastern Australian Childhood Nevus Study. In an agreement study, parents were asked to mark on an anatomic diagram any melanocytic nevi greater than or equal to 2 mm in diameter and greater than or equal to 5 mm in diameter they observed on their child's back prior to the child's examination by a dermatologist; 324 parents responded (a 77% response rate). Standardized slide photographs of each child's back were taken, and melanocytic nevi were counted by an experienced non-medical-examiner upon projection. Agreement was assessed graphically and with the concordance correlation coefficient (r(c)). Parental counts of melanocytic nevi were similar to counts made by the dermatologist (n = 77; for nevi >or=2 mm, r(c) = 0.51; for nevi >or=5 mm, r(c) = 0.78) and counts obtained from the photographs (n = 324; for nevi >or=2 mm, r(c) = 0.68; for nevi >or=5 mm, r(c) = 0.68). Few parents reported false-positive lesions. Parents tended to underestimate the number of melanocytic nevi greater than or equal to 2 mm in diameter (mean difference from dermatologist: -3.2, standard deviation 6.8; mean difference from photographs: -1.1, standard deviation 5.1), particularly when the density of melanocytic nevi was high. Agreement between dermatologist counts and photograph counts was high (for nevi >or=2 mm, r(c) = 0.80; for nevi >or=5 mm, r(c) = 0.87). The authors conclude that parents are capable of counting melanocytic nevi on their children's skin with some validity. In epidemiologic studies of children, counts of melanocytic nevi obtained from standardized photographs have the potential to replace counts made by physicians.

Adolescent↗
PubMed1994

Melanocytic nevi in children. I. Anatomic sites and demographic and host factors.

A survey of benign melanocytic nevi was conducted among schoolchildren in Perth, Western Australia, in 1985, with the aim of describing the prevalence and causes of nevi. Children were recruited from Perth public schools that were chosen to be representative of the socioeconomic and geographic distribution of the population. Of 4,898 eligible children, 2,595 (53%) had all of their nevi counted by one member of a team of five nurses. Analysis was restricted to 2,552 children aged 5-14 years. Children of European origin (i.e., white children), who comprised the majority of the sample (2,376 children), had many more nevi than did children of other ethnic origins. Among white children, the prevalence of nevi increased progressively with age, although the number of nevi per unit of skin area reached a plateau at about 9 years of age. Boys had more nevi at all ages than did girls. The number of nevi per unit of area was highest on the lateral surfaces of the upper limbs and the face and neck, and was lowest on the lower limbs. Children whose parents had been born in Southern Europe were likely to have few nevi. Children with red hair had relatively few nevi, but children with light skin generally had more nevi than children with darker skin. Ability to tan and propensity to burn were also associated with number of nevi, although not in a simple fashion; numbers of nevi were highest in intermediate categories of these two variables. The relation with freckling was also complex; the mean number of nevi increased with increasing freckling until the freckling became moderate to heavy, after which it fell.

Adolescent↗
PubMed2006

Treatment of dysplastic nevi with 5% imiquimod cream, a pilot study.

OBJECTIVE: To assess the clinical and histologic effects of topical imiquimod therapy on dysplastic nevi, and to determine the feasibility of using in vivo confocal microscopy (CSLM) to non-invasively monitor histological response of dysplastic nevi to imiquimod therapy. DESIGN: Single-blinded pilot study with patients not blinded as to treatment status. SETTING: Dermatology Outpatient Clinic, Memorial Sloan-Kettering Cancer Center, New York, NY. PATIENTS: The study population comprised of 10 patients with clinically dysplastic (atypical) nevi and at least 8 large nevi, (> or =5 mm) on their trunk. INTERVENTION: Sixteen weeks of imiquimod 5% cream applied to treatment lesions 3 times per week. MAIN OUTCOME MEASURE: Clinical response as gauged by comparison of baseline and week 20 1:1 standardized photographs for all study nevi and histological assessment of each patient's 4 largest study nevi at completion of therapy. RESULTS: There were no obvious clinical changes in the size and morphology of the study nevi. Subtle changes in nevus color could not be assessed due to imperfect spectral registration of images over the course of the study. Histologically, 4 of 14 treated nevi and 0 of 14 untreated nevi p=0.03 showed a significant relative reduction of junctional and intraepidermal nevocytes accompanied by papillary dermal fibroses and variable inflammation suggestive of partial regression. Non-invasive CSLM imaging of study nevi demonstrated previously reported in vivo features of dysplastic nevi. but the imaging equipment and protocol utilized proved inconsistent across lesions and time. CONCLUSIONS: The histological changes seen in a subset of treated nevi suggest a possible role for the use of topical immune response modifiers for the treatment of dysplastic nevi with the intent of melanoma chemoprevention. The dose regimen of topical imiquimod utilized in this study failed to induce sufficient clinical or histological responses to warrant further study. Targeting of dysplastic nevi and intermediate endpoints for melanoma chemoprevention with more intense and/or prolonged treatment regimens with imiquimod or the use of other immune response modifiers seems promising. Technical improvements are required for the use of non-invasive CSLM imaging in lieu of invasive histology for the study of topical nevus therapies.

Aminoquinolines↗
PubMed1990

Histopathologic spectrum of clinically atypical melanocytic nevi. II. Studies of nonfamilial melanoma.

We studied the clinically most atypical pigmented lesion removed from each of 142 patients with newly diagnosed sporadic melanoma. The specimens were categorized as to the type of nevus, ie, junctional or compound, presence of congenital features, and degree of nuclear atypicality--presence of nuclear enlargement, nuclear pleomorphism, hyperchromatism, and prominent nucleoli--of intraepidermal nevomelanocytes. The frequency of nuclear abnormality was graded as 1 (rare cells), 2 (10% to 50% of cells), or 3 (greater than 50% of cells) for each nuclear parameter. Among all lesions, 42 (29.6%) were junctional nevi, 74 (52.1%) were compound nevi, and 14 (9.9%) were dermal nevi. Eighteen percent of the total were either dysplastic nevi (23 cases) or malignant melanoma in situ (three cases). Fourteen nevi (9.9%) had congenital features. There were 12 junctional and 39 compound nevi and one dermal nevus that exhibited nuclear abnormality, but only four junctional nevi compared with 19 compound nevi had sufficient atypia for a designation of dysplastic nevus. Only two nevi with congenital features demonstrated any nuclear abnormality, and these were clearly nondysplastic. Thus, among nevi surgically removed as the clinically most atypical lesion in this study, compound nevi were much more likely to demonstrate nuclear atypia (and dysplasia) than were other nevi, ie, junctional or dermal nevi, or nevi with congenital features.

Adult↗
PubMed1993

Natural history of dysplastic nevi.

BACKGROUND: Dysplastic nevi are markers of melanoma risk and potential precursors of melanoma. Few studies have addressed the natural history of dysplastic nevi. OBJECTIVE: Our purpose was to describe the changes observed in nevi over time in a cohort of our patients with dysplastic nevi. METHODS: We used a historical cohort design to study 153 patients with dysplastic nevi observed for a minimum of 5 years. Physical examination at completion of the study was compared with baseline overview and close-up photographs. Lesions excised during the study interval were assessed for history of change. RESULTS: Fifty one percent of all evaluated nevi (297 of 593) showed clinical signs of change during an average follow-up of 89 months. New nevi were common in adulthood and continued to form in more than 20% of patients older than 50 years of age. Nevi were observed to become more clinically atypical, less clinically atypical, and disappear in all age groups. In this small cohort rates of nevus change were not correlated with personal or family history of melanoma, sex, or total number of nevi. Total nevus counts and rates of nevus change were correlated with age. CONCLUSION: Dysplastic nevi remain clinically dynamic in adulthood. Our data suggest that the decrease in counts of dysplastic nevi associated with increasing age is only partly explained by the disappearance of nevi over time and probably reflects a tendency to larger numbers of nevi among more recent birth cohorts.

Adolescent↗
PubMed1999

Clinical and histological effect of a single treatment of normal mode alexandrite (755 nm) laser on small melanocytic nevi.

BACKGROUND AND OBJECTIVE: Earlier studies on the treatment of congenital melanocytic nevi have reported the efficacy of Q-switched ruby laser and Nd:YAG lasers. In this study we evaluated the clinical and the histological effects of a single treatment of normal mode (3 msec) alexandrite laser (755 nm) on small melanocytic nevi. MATERIALS AND METHODS: Fourteen patients having 40 nevi entered into the study. Twenty six nevi were clinically followed up after laser treatment for 4 months. Fourteen nevi were biopsied after laser treatment: 8 nevi immediately, 3 nevi after 10 days and 3 nevi after 1 month. RESULTS: At the end of 4 months, 20 (76.92%) nevi attained moderate to significant lightening of color, 5 (19%) nevi had their color matching that of the surrounding skin, one nevus (3.85%) showed very mild hypopigmentation, and 18 (69%) nevi had a surface level similar to the surrounding skin. One nevus healed with keloid formation. Histologically, immediately following laser, there was necrosis of nevus cells in the papillary and uppermost reticular dermis. Nevus cells in the deeper layers of the dermis were not affected. Ten days following laser, the upper dermis showed granulation tissue. One month after laser, there was mild fibrosis in the upper dermis and persistence of nevus cells in the middle and deep dermis. CONCLUSION: These results suggest that normal mode alexandrite laser may clear or cosmetically improve small melanocytic nevi whether congenital or acquired. However, the concern about the recurrence of the nevi and the potential for malignant transformation should be addressed by long-term follow-up studies.

Adult↗
PubMed1991

Seasonal variation in the proliferation fraction of Australian common nevi.

Image cytometry was used to assess seasonal variation in the proliferation fraction of Australian common nevi. Twenty pairs of nevi were evaluated. One member of each pair had been excised during the Australian summer, and the other member of the pair had been excised during the winter. The nevi were matched for age, sex, and body site. From each nevus, 6-microns sections were Feulgen-stained and evaluated with a CAS 200 image analyzer, which was used to obtain DNA histograms. Proliferation fractions were calculated from the histograms. The proliferation fraction of the nevi removed during the winter was 1.65 +/- 0.32%, whereas the proliferation fraction of the nevi removed during the summer was 1.95 +/- 0.42% (p = 0.41). For nevi from sun-exposed sites only, the proliferation rate of nevi excised during the winter was 1.81 +/- 0.39%, and 2.58 +/- 0.39% for nevi excised during the summer (p = 0.11). For nevi from sun-protected sites, there was no difference between winter and summer. When nevi excised during the summer were compared by site, sun-exposed nevi had a proliferation rate of 2.60 +/- 0.48% (p = 0.04). For nevi excised during the winter, there was a much smaller difference between sun-exposed and sun-protected nevi.

Adolescent↗
PubMed2004

Expression of thyrotropin-releasing hormone by human melanoma and nevi.

PURPOSE: Thyrotropin-releasing hormone (TRH) is a tripeptide hormone produced by the hypothalamus in response to hypothyroidism. RNA transcripts for the TRH prohormone have recently been described in melanoma cell lines. To expand these findings, we have examined cultured melanoma cells and melanocytes, human melanoma tumors, and nevi for the expression of TRH. EXPERIMENTAL DESIGN: Five melanoma cell lines were analyzed by reverse transcription-PCR/Southern blotting for preproTRH message. The same melanoma lines and two melanocyte lines were examined by immunocytochemistry for TRH protein expression and for growth response to exogenous TRH. Immunohistochemistry was used to test for TRH protein in sections of 19 melanomas, 33 dysplastic nevi, and 27 benign nevi. RESULTS: TRH message and protein were detected in all melanoma cell lines examined. Melanocytes were also found to express TRH protein. Four of the five melanoma cell lines but neither melanocyte line responded with a increase in proliferation to low concentrations of exogenous TRH. TRH immunoreactivity was observed in 12 of 19 melanomas (63%), 23 of 33 (69.7%) dysplastic nevi, and 14 of 27 (51.9%) benign nevi. Expression in dysplastic nevi was significantly greater than in benign nevi. Upon separate analysis of nevi from melanoma patients, the difference between dysplastic and benign nevi was even more significant. However, in healthy individuals, no difference between dysplastic and benign nevi was observed. Furthermore, dysplastic nevi from melanoma patients had a significantly higher percentage of TRH-positive cells when compared with healthy individuals. CONCLUSIONS: TRH is commonly expressed by melanomas and dysplastic nevi and may function as a melanoma autocrine growth factor. The presence of TRH in dysplastic nevi may be predictive for the development of melanoma. Our findings have significant clinical and biological implications for future research into the early stages of melanoma initiation and progression.

Cell Line, Tumor↗
PubMed2005

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.

Adolescent↗
PubMed1997

Clinically recognized dysplastic nevi. A central risk factor for cutaneous melanoma.

OBJECTIVE: To investigate the relationship of number and type of nevi to the development of melanoma. DESIGN: Case-control study. SETTING: Outpatient clinics in referral hospitals. PATIENTS: Cases were 716 consecutive patients with newly diagnosed melanoma identified at 2 melanoma centers between January 1, 1991, and December 31, 1992. Stratified random sampling of patients from outpatient clinics was used to identify 1014 participating controls of the same age, sex, race, and geographic distribution as the melanoma cases. All study subjects underwent an interview, a complete skin examination, photography of the most atypical nevi, and, if the patient was willing, a biopsy of the most atypical nevus. MAIN OUTCOME MEASURES: Number and type of nevi on the entire body were systematically reported. All diagnoses of clinically dysplastic nevi were confirmed by expert examiners. RESULTS: Risk for melanoma was strongly related to number of small nevi, large nondysplastic nevi, and clinically dysplastic nevi. In the absence of dysplastic nevi, increased numbers of small nevi were associated with an approximately 2-fold risk, and increased numbers of both small and large nondysplastic nevi were associated with a 4-fold risk. One clinically dysplastic nevus was associated with a 2-fold risk (95% confidence interval, 1.4-3.6), while 10 or more conferred a 12-fold increased risk (95% confidence interval, 4.4-31). Congenital nevi were not associated with increased risk of melanoma. CONCLUSIONS: Although nondysplastic nevi confer a small risk, clinically dysplastic nevi confer substantial risk for melanoma. On the basis of nevus number and type, clinicians can identify a population at high risk of this epidemic cancer for screening and intervention.

Adult↗
PubMed2004

Immunophenotype and possible origin of nevi with phenotypical heterogeneity.

Biphenotypical nevi or nevi with phenotypical heterogeneity consist of phenotypically different cell populations in a pattern other than that observed in classical combined nevi or in various maturation stages of banal nevocellular nevi. Besides several well-known entities such as deep penetrating nevi and plexiform spindle cell nevi, this category of pigment cell lesions also harbors fewer delineated lesions such as nevi with atypical dermal nodules (N-ADN) and nevi with a focal atypical epithelioid cell component (N-FAECC). Their worrisome histology may result in a wrong diagnosis of malignancy. In order to discriminate them from malignant melanoma and to shed light on their histogenesis, we analyzed the immunophenotypical profile of 33 N-FAECC, 6 N-ADN, and 10 giant congenital nevi removed shortly after birth, using antibodies directed to S100 protein, gp100, tyrosinase, NKI-C3, Melan-A and Mib-1. In N-FAECC and N-ADN, the large polygonal cells expressed gp100, S100 protein and Melan-A, and reacted with monoclonal antibody NKI-C3. In addition, there was intense tyrosinase expression but no Mib-1 immunoreactivity. Unexpectedly, we observed similar single or clustered, large epithelioid cells in three out of ten giant congenital nevi; these cells showed a similar phenotype to those observed in N-ADN and N-FAECC. Our histological and immunohistochemical data suggest that N-FAECC and N-ADN may reflect different stages of the same disorder. Moreover, their resemblance to the large polygonal cells in congenital nevi may suggest that the histogenesis of N-ADN and N-FAECC may be related to the persistence and expansion of large epithelioid cells in congenital nevi shortly after birth.

Antigens, Neoplasm↗
PubMed1992

Influence of cumulative sun exposure on the prevalence of common acquired nevi.

BACKGROUND: Conflicting evidence exists on the relation between sun exposure and the number of common acquired nevi. The increase in the number of common acquired nevi until early adulthood and their greater concentration on sun-exposed areas suggested that the growth of common acquired nevi is promoted by UV radiation. Nevertheless, it was noticed that although solar exposure accumulates with age, the number of common acquired nevi decreases after the third decade. OBJECTIVE: Our purpose was to examine the relation between the prevalence of common acquired nevi and accumulative sun exposure. METHODS: The number of common acquired nevi on 128 patients with multiple solar keratoses (SK) was compared with their number on 82 control subjects. The existence of SK served as a biologic marker for long-term solar effects. RESULTS: On patients with SK we counted 1285 nevi (mean 10.0 nevi per person) and on control subjects, 1521 nevi (mean 18.5 nevi) (p = 0.0046; Kruskal-Wallis test). The finding that persons exhibiting signs of accumulating sun effects have fewer nevi was maintained irrespective to differences of gender, occupation, and complexion. CONCLUSION: Our data suggest that accumulating solar effects may contribute to the natural maturation and elimination of common acquired nevi in late adulthood.

Aged↗
PubMed2005

Congenital melanocytic nevi: clinical and histopathologic features, risk of melanoma, and clinical management.

Congenital melanocytic nevi occur in approximately 1% of newborns and are usually classified according to their size. Giant congenital melanocytic nevi are most simply defined as melanocytic nevi that are greater than 20 cm in largest dimension; whereas small congenital nevi are defined as melanocytic nevi less that 1.5 cm in largest dimension. Congenital nevi can exhibit distinctive histologic features that can help in differentiating them from common acquired nevi. Giant congenital melanocytic nevi are associated with an increased risk of the development of melanoma. On the other hand, there is evidence of an increased melanoma risk in patients with small congenital nevi. Nevertheless, the risk of malignant transformation in small congenital nevi and the lifetime melanoma risk in patients with small congenital nevi remain controversial. In large part due to inconsistency in the reported literature describing patients with congenital melanocytic nevi, the risk of melanoma in these patients remains unclear and consistent guidelines for clinical management do not exist. We review the literature and comment on the course of management for these patients at the Massachusetts General Hospital Pigmented Lesion Clinic.

Abnormalities, Multiple↗
PubMed1994

Microcirculation architecture of melanocytic nevi and malignant melanomas of the ciliary body and choroid. A comparative histopathologic and ultrastructural study.

PURPOSE: This study was designed to (1) describe the vascular patterns of ciliary body and choroidal nevi by light microscopy, (2) compare the vascular ultrastructure of nevi with vessels of the normal uvea and uveal melanomas, and (3) compare the behavior of ciliochoroidal melanomas with and without a nevus-like vascular architecture. METHODS: After delineating the vascular patterns of 23 choroidal and ciliary body nevi by light microscopy, the authors identified 49 melanomas that had the same vascular patterns as nevi from a previously published series of 234 uveal melanomas. The survival of these 49 patients who had melanomas with a nevus-like vascular architecture was compared with the 185 patients who had melanomas that lacked this vascular profile. RESULTS: By light microscopy, the only vascular patterns identified in nevi are "normal" vessels, zones of avascularity ("silent" pattern), straight, and parallel vessels; closed vascular loops and networks were not detected in nevi. By transmission electron microscopy, the vascular basement membrane of malignant melanomas was multilaminar, fragmented, and significantly thicker than in normal eyes or nevi. None of the patients with nevi died of metastatic disease. Fourteen percent of patients whose melanomas had the same vascular profile as nevi died of metastatic disease, whereas 32% of patients whose melanomas had vascular patterns other than those seen in nevi died of metastatic melanoma (P = 0.012). CONCLUSIONS: The microcirculation architecture marks tumor progression in uveal melanocytic lesions by light and electron microscopy. In the spectrum of these lesions, nevi are benign, melanomas that have the same vascular profile as nevi have an intermediate biologic behavior, and melanomas with vascular networks are strongly associated with death due to metastatic disease.

Adolescent↗
PubMed1997

Changes in size of melanocytic nevi during pregnancy.

BACKGROUND: The relation between pregnancy, melanocytic nevi, and malignant melanoma is ambiguous. It has been reported that nevi grow and darken during pregnancy. Several recent studies have shown that malignant melanomas diagnosed during pregnancy are thicker than those not associated with pregnancy. This may be partially due to a delay in diagnosis because of the opinion that benign nevi change during pregnancy. OBJECTIVE: Our purpose was to photographically document any change in size of melanocytic nevi during pregnancy. METHODS: Twenty-two women were entered into the study during the first trimester of pregnancy and examined again in the third trimester. All nevi 2 mm or larger on their back were documented and photographed. Photographs were then compared and nevi measured for change in diameter. RESULTS: Of 129 nevi, only eight nevi (6.2%) changed in diameter from the first to the third trimester. The mean change in size of all nevi studied was zero. Of the eight nevi that did change in size, four increased by 1 mm and four decreased by 1 mm. CONCLUSION: Our study suggests that pregnancy is not associated with any significant change in size of melanocytic nevi. Patient characteristics (age, pregnancy number, skin type) and nevi characteristics (location, number) did not correlate with any change in size.

Adult↗