Multiple primary melanomas

BACKGROUND: Patients with clinically diagnosed dysplastic nevi or a family history of melanoma with or without histologically diagnosed dysplastic nevi seem to be at higher risk for the development of multiple melanomas. OBJECTIVE: Our purpose was to determine which factors increased the risk for the development of subsequent melanomas. METHODS: This was a retrospective study in 56 patients with 157 melanomas. RESULTS: Early age at onset (58.9%), clinically diagnosed dysplastic nevi (82.0%), a histologically diagnosed dysplastic nevus (64%), family history of clinically diagnosed dysplastic nevi (70.8%) or melanoma (64.7%) and a histologically diagnosed dysplastic nevus in combination with a family history of melanoma (48%) were found in a high percentage of patients. The mean age at diagnosis was 38.2 years. The mean interval between the first and second melanoma was 34.3 months. Of the second melanomas, 76.8% developed in a different anatomic region from the first melanomas. The mean tumor thickness (Breslow) decreased from 1.11 mm for the first melanomas to 0.90 mm for the second melanomas. CONCLUSION: The results suggest that genetic factors might be involved in a certain subset of patients in whom melanomas develop early and successively.     

Clinical and histopathologic analyses of pigmented macular lesions on the soles of Japanese--proposal of a clinical guideline for detection of early malignant melanoma on the sole

Of 92 pigmented macular lesions on the soles of Japanese, 88 lesions were histologically confirmed to be melanocytic: 65 ordinary acquired melanocytic nevi, 9 congenital melanocytic nevi, 5 dysplastic nevi, and 5 possible and 4 definite lesions of early malignant melanomas. None of the ordinary acquired melanocytic nevi were more than 7 mm in maximum diameter. Excluding congenital melanocytic nevi, there were 8 lesions whose greatest diameters were more than 7 mm: 2 dysplastic nevi, and 2 possible and 4 definite lesions of early malignant melanoma. Judging from the data obtained in this study, we propose the following clinical guideline for the detection of early lesions of malignant melanoma on the sole. If the pigmented lesions have no possibility of being congenital melanocytic nevus, black heel, lesions of Peutz-Jeghers syndrome, or 5-FU induced lesions, measure the maximum diameters. 1) Lesions with a diameter of more than 7 mm should be excised for histological evaluation. 2) Lesions with a diameter between 6 and 7 mm should be examined histologically when they show conspicuous irregularity in shape, color and/or border or are observed on the soles of a patient older than 50.     

PREVALENCE OF DYSPLASTIC NEVI IN HEALTHY YOUNG MEN

Young white men (1176 men, mean age 20 years, age range from 18 to 26 years) were examined for dysplastic nevi. In 78 patients (6.63%), 107 clinically dysplastic nevi were observed, demonstrating all three NIH criteria (diameter greater than 5mm, irregularities of border, irregularities of color) suggestive for clinically dysplastic nevi. Of these, 71 nevi in 52 patients were excised and examined histologically, 46 nevi in 26 patients were not excised due to lack of patients' consent. Fifty-two of 78 (66.6%) patients with clinically dysplastic nevi agreed to excision. In these, seven nevi (13.5% of patients or 9.86% of all nevi excised) were confirmed by histology. According to these data, three additional patients with dysplastic nevi would have been expected among the 26 patients who refused surgery. Referring to the entire study group, the prevalence of dysplastic nevi in young white men is expected to be 0.85%.     

Dysplastic nevus in histologic contiguity with acquired nonfamilial melanoma. Clinicopathologic experience in a 100-bed hospital

In the face of alarming rates of increase in melanoma worldwide, dysplastic nevi, especially any that are clinically changing in size, color, or borders, may be regarded as playing a potential role in the progression to a tumor stage. Dysplastic nevi are known to occur in multiples in family members of heritable malignant melanoma. Intraepidermal atypical melanocytes fulfilling the criteria of the dysplastic nevus were seen in histologic contiguity with superficial malignant nonfamilial melanomas in six of 13 patients. With one exception, all melanomas in this study that were associated with histologically contiguous dysplastic nevi were relatively thin, allowing identification of the melanoma at a potentially curable stage.     

Clinical diagnosis of dysplastic melanocytic nevi: A clinicopathologic correlation

A prospective, community practice-based, clinicopathologic correlation was undertaken in 165 melanocytic nevi excised from a group of forty-three patients, each patient having previously had at least one clinically suspected and histologically confirmed dysplastic melanocytic nevus. Eighty-two percent of seventy-two lesions with histologic evidence of mild dysplasia had been diagnosed correctly as such clinically. The accuracy of clinical diagnosis of moderate dysplasia was low (20%); however, all cases of severe dysplasia with or without in situ melanoma were diagnosed correctly. In 75% of all cases in which dysplasia of any degree was diagnosed clinically, histologic evidence of dysplasia was found. In order to investigate further the clinical features of these nevi, 175 color enlargements of histologically confirmed dysplastic melanocytic nevi were examined. The following clinical features were found to be most common: ill-defined border (90%), irregularly distributed pigmentation (84%), maximum diameter greater than 5.0 mm (72%), erythema (64%), and accentuated skin markings (63%). Increasing darkness and confluence of pigmentation in these dysplastic melanocytic nevi correlated with increasing severity of dysplasia. We conclude that careful clinical examination of individual melanocytic nevi will separate severe dysplasia with or without in situ melanoma from low-grade (mild or moderate) dysplasia in a high percentage of nevi from patients with the dysplastic nevus syndrome. Clinical examination will yield a diagnosis of dysplasia in approximately 75% of nevi from such patients in whom histologic evidence of dysplasia is present. Clinical examination constitutes a practical and sufficiently reliable method for the assessment of melanocytic nevi in patients with the dysplastic nevus syndrome.     

Congenital nevus cell nevi of the skin--a nomenclatural and therapeutic problem

The alarming increase in the incidence of malignant melanomas has caused interest to be focused on some of the precursors or tumor markers, such as dysplastic nevi or congenital nevocytic nevi. Both clinically and histologically, as well as by the incidence of malignancy, three groups of congenital nevocytic nevi may be distinguished. Small nevi (diameter less than 1.5 cm) are frequent, but it remains to be elucidated whether they involve an increased risk of malignancy. On the basis of differences in potential malignancy the larger congenital nevocytic nevi may be subdivided into two forms. Malignant melanomas occur more frequently and earlier in life in large nevi (diameter greater than 20 cm) compared with medium-sized nevi (diameter 1.5-20 cm). Medium-sized congenital nevi can usually be removed without considerable problems. In very large nevi, however, surgical treatment is more difficult. Since the risks involved in performing radical surgery in children may bear no relationship to possible benefits, repeated clinical examinations, detailed photographic documentation and immediate excision of any suspicious skin areas must be undertaken in such patients.     

Correlation between clinical atypia and histologic dysplasia in acquired melanocytic nevi.

BACKGROUND: The validity of clinical and histologic criteria in identifying dysplastic nevi is controversial. Recognition of the dysplastic nevus as a distinct clinicopathologic entity requires demonstration of significant agreement between clinical atypia and histologic dysplasia. OBJECTIVE: We attempted to determine the correlation between clinical atypia and histologic dysplasia in acquired melanocytic nevi and to evaluate the sensitivity and specificity of clinical criteria for dysplastic nevi when compared with histopathologic features. METHODS: A total of 940 acquired melanocytic nevi 3 mm in diameter or larger were selected by initially choosing clinically unequivocal dysplastic and nondysplastic nevi and then, from these, histologically unequivocal dysplastic and nondysplastic lesions. The level of concordance between clinical atypia and histologic dysplasia was estimated by kappa statistics. RESULTS: Nevi were classified as clinically dysplastic (n = 499) or nondysplastic (n = 441). On the basis of histologic features, 739 were classified as dysplastic and 201 as nondysplastic. Agreement between clinical atypia and histologic dysplasia was found in 432 nevi, that is, a sensitivity of 58.4% (3-5 mm = 27.2%, >5 mm = 69.8%). Agreement between clinical and histologic criteria on the absence of dysplasia was found in 134 nevi, a specificity of 66.6% (3-5 mm = 92.4%, >5 mm = 47.9%). The kappa value was 0.17 (3-5 mm = 0.14, >5 mm = 0.10). CONCLUSION: The limited sensitivity and specificity together with the negligible kappa value indicate a poor agreement between clinical and histologic diagnoses of dysplastic nevus. The dysplastic nevus cannot be considered a distinct clinicopathologic entity because histologic dysplasia is found in a range of nevi that may or may not show clinical atypia.     

High-resolution laser Doppler perfusion imaging aids in differentiating between benign and malignant melanocytic skin tumours

Malignant melanomas are characterized by heterogeneity and asymmetry as well as by a higher density of blood vessels than benign pigmented tumours. The aim of this study was to evaluate the benefit of high-resolution laser Doppler perfusion imaging (LDPI) in the differential diagnosis of pigmented skin tumours. One-hundred-and-eighty-nine patients were examined with the LDPI, 22 with malignant melanomas, 39 with clinically suspicious dysplastic melanocytic naevi and 27 with basal cell carcinomas. Following examination, the tumours were excised and examined histologically. A control group of 101 melanocytic naevi showed clinically and, with epiluminescence microscopy, definitely benign criteria. These naevi were not excised. In malignant melanomas there was a 3.6+/-1.5 times higher perfusion than in healthy skin. The corresponding figures for clinically suspicious melanocytic naevi and basal cell carcinomas were 2.2+/-1.1 and 2.0+/-0.7, respectively. The increase in flow in malignant melanomas was significantly higher than in clinically suspicious melanocytic naevi and basal cell carcinomas (p < 0.001). All malignant melanomas showed at least 1.8 times higher flow values than healthy skin. When this value is taken as the basis for the diagnosis "benign or malignant", the LDPI proved a sensitivity of 100% and a specificity of 85%. If only the distinction between malignant melanomas and clinically suspicious naevi is considered, the specificity is reduced to 48%. There was no correlation between tumour thickness and increase in the mean perfusion of malignant melanomas (r = 0.14; p = 0.5). High-resolution LDPI can be used as an additional automatic screening method.     

The frequency of histologically dysplastic nevi in 199 pediatric patients

Many uncertainties surround the definition, frequency, and significance of dysplastic nevi in children. Consequently the management of dysplastic nevi in the pediatric population has been largely derived from the studies of adults. Biopsies are usually performed on this young age group because of lesion change or abnormal appearance. One might therefore assume that the frequency of histologically diagnosed dysplastic nevi would be higher in children than in adults. We decided to attempt to verify this assumption by determining the frequency of dysplastic nevi diagnosed histologically in the pediatric population. To do this we reviewed 199 cutaneous pathology reports of nevi removed from patients less than 18 years old and submitted to a community-based dermatopathology laboratory. The diagnosis of dysplastic nevus was made based on histologic criteria recommended by the World Health Organization Melanoma Program. We found that 3 of 199 nevi submitted for histologic analysis met the histologic criteria for dysplastic nevus. There were no melanomas. Our data suggest that there is an extremely low frequency of histologically confirmed dysplastic nevi within the general pediatric population.     

Intraepidermal distribution patterns of melanocytes in the melanocytic lesions on the sole: proposed criteria for histopathologic diagnosis of plantar malignant melanoma in situ

Eighty-eight melanocytic lesions on the soles of Japanese were histologically investigated. Increased numbers of solitary melanocytes above the basal layer of the epidermis were often found in the benign melanocytic nevi on the sole: in 5 lesions of 9 congenital melanocytic nevi, 22 of 65 acquired melanocytic nevi, and 1 of 5 dysplastic nevi. In addition, a moderate degree of nuclear atypia of proliferating melanocytes was frequently observed in the benign melanocytic nevi on the sole: in 3 lesions of 9 congenital melanocytic nevi, 17 of 65 acquired melanocytic nevi, and 2 of 5 dysplastic nevi. Therefore it cannot be said that increased numbers of solitary atypical melanocytes above the basal layer is a characteristic histologic feature of early malignant melanoma in situ. Combining the intraepidermal distribution patterns of melanocytes and maximum diameter of the lesion, we propose criteria for histopathologic diagnosis of plantar malignant melanoma in situ.     

Cyanoacrylate skin surface stripping: an improved approach for distinguishing dysplastic nevi from malignant melanomas

We present a novel approach for improving the management of patients with pigmented neoplasms including malignant melanomas and dysplastic nevi. A cohort of 215 dysplastic nevi and malignant melanomas was studied by cyanoacrylate skin surface stripping (CSSS) and conventional histology. Presence of atypical melanocytes was found in the stratum corneum in more than 95% of malignant melanomas and was always absent in dysplastic nevi. We conclude that this non-invasive technique is rapid, easy to perform, and inexpensive. Its specificity and sensitivity are high enough to be considered by clinicians as an aid for distinguishing dysplastic nevi from malignant melanomas. We recommend this ancillary technique as a screening procedure though not as a substitute for conservative excisional biopsy, when doubt persists in the diagnosis of atypical pigmented neoplasms.     

How well do physicians recognize melanoma and other problem lesions?

The alarming increase in the incidence of cutaneous malignant melanoma in the United States emphasizes the importance of its early detection and treatment. Early detection requires accurate clinical recognition of both malignant and precancerous skin lesions (dysplastic nevi). This study presents data on dermatologists' and nondermatologists' ability to diagnose skin lesions. A total of 105 nondermatologist physicians, from first-year residents to practicing physicians, and forty-eight dermatologists were asked to identify color slides or photographs of eleven cutaneous lesions, including malignant melanomas, dysplastic nevi, and innocuous lesions such as seborrheic keratoses and common moles. Diagnosis of cutaneous lesions was generally inaccurate among nondermatologists. Only 38% correctly identified four or more of the six melanomas as melanoma of any type, and 58% were unable to diagnose dysplastic nevi. Only 17% categorized their relevant training as excellent or good. Improved training in the diagnosis of skin lesions for practicing physicians and house staff is required if mortality from malignant melanoma is to be decreased in the United States.     

The relationship between melanocytic nevi and malignant melanoma

In conclusion, although there are data, some quite convincingly implicating dysplastic nevi and congenital nevi (particularly "giant") as "precursors" of malignant melanomas, our ability to predict the magnitude of these associations is lacking. Thus, until additional basic and clinical research data are forthcoming, any recommendation to prophylactically remove all congenital nevi or all dysplastic nevi in order to decrease the incidence of malignant melanoma is premature. In regard to congenital nevi, evidence exists that giant (larger than 20 cm in diameter) congenital nevi may have a significant risk factor so as to warrant, when feasible, prophylactic excision of such lesions. In our opinion, no uniform recommendation can be made at this time for the management of small and medium-sized congenital nevi. Patients with familial dysplastic nevus syndrome should be followed carefully and educated concerning the early detection of malignant melanoma. Patients with sporadic dysplastic nevus syndrome deserve further study to enable us to accurately determine their risk of developing malignant melanoma.     

Melanoma screening: report of a survey in occupational medicine

BACKGROUND: Epidemiological studies concerning melanoma are most often performed by general practitioners and dermatologists in patients previously aware of the risk of nevi. OBJECTIVE: To determine the efficiency of early detection of melanoma by occupational medicine specialists trained in the use of ABCDE criteria during annual systematic examination of workers. METHODS: A total of 370 subjects with suspect lesions that demonstrated at least 2 of 5 ABCDE criteria were selected from 65000 employees examined; these subjects were requested to see their physician about possible excision. Of the 370 subjects, 273 (73.8%) were seen at a second-year follow-up visit to determine their outcome. RESULTS: Among the 273 subjects who were seen again, 172 (63.0%) had consulted a physician. For the 101 subjects who had not seen a physician, the main reason was the negligence (86.1%). A total of 353 atypical nevi were observed. The mean number of ABCDE criteria noted per lesion was 2.6. Lesion diameter greater than 6 mm was the most frequent (80.5%) and enlargement the least frequent criteria seen; heterochromous coloration and diameter greater than 6 mm was the most common association (54.5%). Five histologically confirmed melanomas were found among nevi excised in 78 subjects. CONCLUSION: This screening approach seems efficient for the early detection of melanoma, demonstrating an incidence of 7.7 per 100000 vs. 9 per 100000 in the general French population.     

Melanocytic nevi and malignant melanoma

It has been known for a long time that melanoma can have its origin in congenital or acquired melanocytic nevi. In regard to congenital nevi, there is sufficient evidence to state that large lesions (those greater than 20 cm in diameter) have a significant risk factor that is several-fold greater than for common acquired nevi. Prophylactic excision of such lesions should be strongly considered when it is feasible, but individual circumstances must be taken into account. The risk factors for small and medium-sized congenital nevi have not been accurately determined; therefore, no uniform recommendation can be made regarding their management. There is no objective evidence to indicate that common acquired nevi in any particular anatomic sites, such as volar or genital skin, are at greater risk for the development of melanoma than are any others. Patients with familial dysplastic nevus syndrome must be identified and followed carefully in order to recognize and eradicate evolving and early melanomas. The concept of the sporadic dysplastic nevus syndrome is intriguing and deserves careful study to further define the clinical and histologic diagnostic criteria that will enable accurate determination of its prevalence and risk factors.     

Dermatoscopy of "dysplastic nevi": a beacon in diagnostic darkness

The sequential progression model for melanocytic tumours from common nevus to malignant melanoma was proposed by Clark almost 30 years ago. The "dysplastic nevus" has frequently been considered a logical offspring of this concept and as a direct precursor of melanoma, analogous to the epithelial dysplasia-carcinoma sequence. Despite the use of modern molecular methods, there is no consensus as to if the dysplastic nevus represents a true precursor lesion of melanoma, a separate distinct type of nevus, or a diagnostic dilemma. Currently, the concept of melanocytic dysplasia remains subject to confusing definitions at all levels of the diagnostic process, i.e. clinical appearance, dermatohistopathology, and molecular biology. In this review, we collect evidence that nevi fulfilling Clark and Elder's classic histological criteria mostly represent "endpoints" of nevocytic evolution, whereas a minority of "dysplastic nevi" represent true melanoma precursors. The unsolved dilemma is that neither clinical, histopathological nor molecular criteria exist to make a distinction between dysplastic nevi and early melanomas. Our analysis of the current knowledge on dysplastic nevi shows that dermatoscopy remains the only quantifiable, easily applicable and reproducible diagnostic tool to approach the problem. Due to a "quantum leap" in optical resolution, objective scores can be established, e.g. the total dermatoscopy score (TDS) according to the ABCD rule, and documentation of changes over time are possible by digital image storage devices. Although dermatoscopy does not solve the dilemma of discriminating early, basically feature-less melanomas from dysplastic nevi, and it does not prove that dysplastic nevus is a distinct entity, it helps make melanocytic tumours with unclear malignant potential a manageable disease.     

Laypersons' perceptual discrimination of pigmented skin lesions

BACKGROUND: Most cutaneous malignant melanomas of the skin are visible and should, at least in theory, be possible to detect with the naked eye. OBJECTIVE: This study was conducted to learn more about laypersons' ability to discriminate between benign pigmented lesions and malignant ones. METHODS: Four groups of laypersons (n = 120) were asked to evaluate pictures of different types of pigmented skin lesions, before and after they received information about the ABCD (asymmetry, border irregularity, color variegation, and diameter greater than 6 mm) criteria, with respect to the necessity of action. RESULTS: The respondents made adequate assessments of melanomas but overestimated the danger of benign pigmented skin lesions. Information about the ABCD criteria enhanced their ability to make adequate assessments. CONCLUSION: People seem to make adequate decisions concerning how to act if they have a melanoma. On the other hand, common moles and dysplastic nevi were harder to discriminate. Providing information to the public about the features of melanomas, in accordance with the ABCD criteria, might help laypersons in their perceptual discrimination of skin lesions.     

Clinical guidelines for the early detection of plantar malignant melanoma

Of 144 pigmented lesions excised from the soles of Japanese patients, 140 were melanocytic. Apart from congenital melanocytic nevi, only a few benign acquired melanocytic nevi on the sole were more than 7 mm in maximum diameter and none exceeded 9 mm. In contrast, all plantar malignant melanomas, including malignant melanoma in situ, were 9 mm or more in maximum diameter. In addition, the majority of plantar melanocytic lesions excised from patients who were older than 50 years of age were malignant melanoma. On the basis of these data, we propose clinical guidelines for the early detection of plantar malignant melanoma.     

Sensitivity of diagnosis of malignant melanoma: A clinicopathologic study with a critical assessment of biopsy techniques

Although most examples of cutaneous malignant melanoma are easily recognized by their clinical appearances, in some cases this serious neoplasm may clinically simulate other less serious forms of skin cancer or benign processes. This study was undertaken to assess both the sensitivity of clinical diagnosis of cutaneous malignant melanoma and the efficacy of biopsies of clinically unsuspected melanomas in yielding specimens on which complete and accurate histologic assessments could be made. A retrospective analysis of 1784 cases of histologically proven melanomas diagnosed between 1985 and 1990 was performed in search of lesions not clinically suspected. Biopsy techniques used to sample these lesions were subjected to critique of their efficacy in yielding specimens that could be accurately diagnosed and completely assessed histologically. Of 1784 histologically proven primary cutaneous melanomas, 583 were not clinically suspected, yielding a sensitivity of 67%. Clinical diagnosis included nevi (33%), no diagnosis (17%), multiple diagnoses (13%), basal cell carcinoma (12%), keratosis (9%), and lentigo (9%) among others. The biopsy methods used to sample these lesions were shave (56%), excisional (24%), punch (11%), curettage (2%), and undetermined (6%). Eighty-six percent of shave biopsies could be accurately assessed while only 32% of punches and no curettages provided sufficient material for both definitive and complete evaluation of melanomas. Eighteen percent of specimens histologically reviewed were considered inadequate for complete evaluation. In 34%, the actual diagnosis of melanoma was uncertain because of inability to assess diagnostic features as a consequence of the biopsy technique. Melanoma may be unsuspected clinically in a significant number of cases and may be mistaken for less serious cutaneous neoplasms.(ABSTRACT TRUNCATED AT 250 WORDS)     

Not diagnosable malignant melanomas

Of the 3574 malignant melanomas treated in Hornheide between December 1981 and August 1990 (not including preinvasive cases) 97 were not immediately recognized. These tumours did not look like melanomas. In 72% they were smaller than 10 mm in diameter, and in 20%, smaller than 5 mm. Clark's so often quoted "pencil rule" should no longer be used as an aid to exclusion of invasive melanoma. Localization of the unrecognized melanomas was on the head and neck in 22% of cases. In 37%, the patients were under the age of 40 years. No less than 25% of the patients had multiple melanomas. Many of these melanomas. Many of these melanomas were thin tumours (less than 0.75 mm in 55% and less than 1.5 mm in 77%). This explains why more than 50% of the lesions are described as "macules". The most common incorrect diagnoses were dysplastic naevi (44%) and common (23%) naevi. The most important anamnestic criteria are the patients' own statements about changes in size, colour and shape. These "dynamic" elements must be more carefully observed and documented during process of the clinical diagnosis.