Melanoma in Western Australia in 1980-81: incidence and characteristics of histological types

Melanoma coexisting with solar elastosis: a potential pitfall in the differential diagnosis between nevus and melanoma

Melanomas, like nonmelanoma skin cancers, are known to be causally related to sun exposure. It is therefore not surprising to see benign nevi and melanomas in a background of solar damage, which at times may complicate their distinction. Because of their long-standing nature, nevi often occur before the development of solar elastosis and as such are intimately associated with the solar elastosis. In contrast, visible solar elastosis often occurs before the development of melanoma, in which case the band of solar elastosis is displaced downward from the overlying invasive melanoma and/or its host response. We describe 4 cases in which invasive melanoma cells were intimately admixed with actinically damaged elastin fibers in the absence of a prominent host response. In each case, melanoma cells were admixed with prominent solar elastosis and lacked a significant host response, suggesting that they were either histiocytes or an associated melanocytic nevus. Recognition of this potential pitfall may be helpful in the diagnosis of primary/in-transit/satellite/metastatic melanoma as well as when evaluating marginal status and determining Breslow thickness.

Association of Interferon Regulatory Factor-4 Polymorphism rs12203592 With Divergent Melanoma Pathways

BACKGROUND

Solar elastosis and neval remnants are histologic markers characteristic of divergent melanoma pathways linked to differences in age at onset, host phenotype, and sun exposure. However, the association between these pathway markers and newly identified low-penetrance melanoma susceptibility loci remains unknown.

METHODS

In the Genes, Environment and Melanoma (GEM) Study, 2103 Caucasian participants had first primary melanomas that underwent centralized pathology review. For 47 single-nucleotide polymorphisms (SNPs) previously identified as low-penetrant melanoma risk variants, we used multinomial logistic regression to compare melanoma with solar elastosis and melanoma with neval remnants simultaneously to melanoma with neither of these markers, excluding melanomas with both markers. All statistical tests were two-sided.

RESULTS

IRF4 rs12203592 was the only SNP to pass the false discovery threshold in baseline models adjusted for age, sex, and study center. rs12203592*T was associated positively with melanoma with solar elastosis (odds ratio [OR] = 1.47, 95% confidence interval [CI] = 1.18 to 1.82) and inversely with melanoma with neval remnants (OR = 0.65, 95% CI = 0.48 to 0.87) compared with melanoma with neither marker (P global = 3.78 x 10(-08)). Adjusting for phenotypic characteristics and total sun exposure hours did not materially affect rs12203592's associations. Distinct early- and late-onset age distributions were observed in patients with IRF4 rs12203592 [CC] and [TT] genotypes, respectively.

CONCLUSIONS

Our findings suggest a role of IRF4 rs12203592 in pathway-specific risk for melanoma development. We hypothesize that IRF4 rs12203592 could underlie in part the bimodal age distribution reported for melanoma and linked to the divergent pathways.

Solar elastosis and cutaneous melanoma: a site-specific analysis

Cutaneous melanomas are postulated to arise through at least two causal pathways, namely the "chronic sun exposure" and "nevus" pathways. While chronic sun exposure probably causes many head/neck melanomas, its role at other sites is unclear. In a population-based, case-case comparison study conducted in Brisbane, Australia, we determined the prevalence and epidemiologic correlates of chronic solar damage in skin adjacent to invasive, incident melanomas on the trunk (n = 418) or head/neck (n = 92) among patients aged 18-79 in 2007-2010. Participants self-reported information about environmental and phenotypic factors, and a dermatologist counted nevi and actinic keratoses. Dermatopathologists assessed solar elastosis adjacent to each melanoma using a four-point scale (nil, mild, moderate, marked), and noted the presence or absence of adjacent neval remnants. We measured associations between various factors and solar elastosis using polytomous logistic regression. Marked or moderate solar elastosis was observed in 10% and 27%, respectively, of trunk melanomas, and 60% and 17%, respectively, of head/neck melanomas. At both sites, marked elastosis was positively associated with age (p(trend)  < 0.0001) and inversely associated with neval remnants (p(trend)  < 0.001). For trunk melanomas, marked elastosis was associated with highest quartiles of total sun exposure [odds-ratio (OR) = 5.47, 95% confidence interval (CI) = 1.08-27.60] and facial freckling (OR = 2.98, 95% CI = 1.17-7.56), and inversely associated with deeply tanning skin (OR = 0.29, 95% CI = 0.08-1.11) and high nevus counts (OR = 0.08, 95% CI = 0.01-0.66). Mostly similar associations were observed with moderate solar elastosis. About one in three trunk melanomas in Queensland have evidence of moderate-to-marked sun damage, and they differ in risk associations from those without.

Changes in the presentation of nodular and superficial spreading melanomas over 35 years

BACKGROUND

Nodular melanoma (NM) may be biologically aggressive compared with the more common superficial spreading melanoma (SSM), with recent data suggesting underlying genetic differences between these 2 subtypes. To better define the clinical behavior of NMs, the authors compared their clinical and histopathologic features to those of SSMs at their institution, a tertiary referral center, over 3 decades.

METHODS

A total of 1,684 patients diagnosed with 1,734 melanomas were prospectively enrolled. Of these, 1,143 patients (69% SSM, 11% NM, 20% other) were diagnosed between 1972 and 1982; 541 patients (54% SSM, 23% NM, 23% other) were diagnosed between 2002 and the present. Differences between the features of NM and SSM within each time period as well as changes over time were analyzed.

RESULTS

The authors found that SSMs are now diagnosed as thinner lesions (P < .0001) with a low incidence of histologic ulceration (P < .0001), whereas there was no significant change in the median tumor thickness or ulceration status of NMs over time (P = .10, P = .30, respectively). The median age at diagnosis of NM, however, did significantly increase over time (51 years to 63 years, P < .01). The median duration of NMs was reported to be only 5 months compared with 9 months in SSM patients.

CONCLUSIONS

The authors' data suggest that improvements have been made in the early detection of SSM but not NM. Modifications of current screening practices, including increased surveillance of high-risk patients with an emphasis on the "E" for "evolution" criterion of the ABCDE acronym used for early detection of melanoma, are thus warranted.

Distribution of clinical-pathological types of cutaneous melanomas and mortality rate in the region of Passo Fundo, RS, Brazil

OBJECTIVE

To describe the characteristics of all cases of primary cutaneous melanoma during the period 1995-2001, registered at pathology departments in the region of Passo Fundo.

METHODS

The sample studied consisted of 229 primary cutaneous melanoma lesions, identified by anatomopathological reports, in 218 patients. The variables evaluated were: sex, age, anatomical site, histological type, level of invasion and tumor thickness. The rate of incidence, mortality and survival curve were calculated.

RESULTS

The most frequent tumor site was in the back of men (49.5%) and in the lower limbs of women (33.1%). The most frequent clinical-pathological type for both sexes was the superficial expansive type (superficial spreading) at 61.6%. The level of invasion was higher in men, using Clark level III (30.3%), than in women. In women the most frequent level of invasion was Clark level II (33.1%). Of the total number of lesions, 198 (47.2%) were </= 1 mm thick, and 23.2% of the men had thicker lesions (> 4 mm) than the women. The incidence was 5.67 per 100,000 patients-year during this period and the mortality rate was 2.16 per 100,000 patients-year.

CONCLUSIONS

In the sample studied the most common sites were in the back of men and in the legs of women. The predominant type clinical-pathological was superficial spreading.

Sun exposure and host phenotype as predictors of cutaneous melanoma associated with neval remnants or dermal elastosis

Recent research suggests that cutaneous melanomas may arise through 2 distinct pathways, characterized by chronic sun exposure on one hand and nevus-prone phenotype of the host on the other. Two histological characteristics of melanoma consistent with these divergent origins are dermal elastosis in adjacent skin and neval remnants contiguous with the tumor, respectively. To further explore causal heterogeneity in melanoma, we compared sun exposure histories and phenotypic characteristics among a population-based sample of patients newly diagnosed with cutaneous melanoma with and without contiguous neval remnants or dermal elastosis. Tissue blocks were obtained for 141 patients: 53 with superficial spreading melanoma (SSM) of the back, 42 with SSM of head and neck (H & N), and 39 and 7 with lentigo maligna/lentigo maligna melanoma (LM/LMM) of the H & N and back, respectively. Melanomas of the H & N were less likely than those on back to have neval remnants (adjusted OR 0.6, 95% CI 0.3-1.4), but were significantly more likely to have dermal elastosis (adjusted OR 9.3, 95% CI 3.5-25). In site-specific analyses, we found that H & N melanomas with neval remnants were more likely than those without neval remnants to arise in people with more than 60 nevi (adjusted OR 2.1, 95% CI 0.3-14.3), but were less likely to arise in those with more than 20 actinic keratoses. Less marked associations were observed for melanomas of the back. High levels of sun exposure strongly predicted dermal elastosis for H & N melanomas (OR 22.5, 95% CI 2.1-245), but not for melanomas of the back (OR 2.1, 95% CI 0.4-11). We conclude that melanomas with different histologic characteristics have different risk factor profiles, particularly on the head and neck. These data accord with the hypothesis that melanomas arise through different causal pathways.

Increasing incidence of lentigo maligna melanoma subtypes: northern California and national trends 1990-2000

Worldwide, lentigo maligna melanoma (LMM) comprises 4%-15% of cutaneous melanoma and occurs less commonly than superficial spreading or nodular subtypes. We assessed the incidence of melanoma subtypes in regional and national Surveillance, Epidemiology, and End Results (SEER) cancer registry data from 1990 to 2000. Because 30%-50% of SEER data were not classified by histogenetic type, we compared the observed SEER trends with an age-matched population of 1024 cases from Stanford University Medical Center (SUMC) (1995-2000). SEER data revealed lentigo maligna (LM) as the most prevalent in situ subtype (79%-83%), and that LMM has been increasing at a higher rate compared with other subtypes and to all invasive melanoma combined for patients aged 45-64 and > or =65 y. The SUMC data demonstrated LM and LMM as the only subtypes increasing in incidence over the study period. In both groups, LM comprised > or =75% of in situ melanoma and LMM > or =27% of invasive melanoma in men 65 y and older. Regional and national SEER data suggest an increasing incidence of LM and LMM, particularly in men > or =age 65. An increased incidence of LM subtypes should direct melanoma screening to heavily sun-exposed sites, where these subtypes predominate.

Etiologic factors associated with p53 immunostaining in cutaneousmalignant melanoma

Findings from a case-control study of cutaneous malignant melanoma (CMM) in Queensland, Australia, suggest that melanomas exhibiting p53 immunostaining possess different risk factors from those of other melanomas. To further explore this hypothesis, a case-only analysis of risk factors for p53 immunostaining with anti-p53 MAb DO-7 was undertaken in 523 people diagnosed with CMM in Canada and Australia. Phenotypic factors and past sun exposure were measured using a self-administered questionnaire and telephone interview. The presence of strong p53 staining (>10% of cell nuclei positively stained vs. <1% staining) was positively associated with some indicators of high cumulative sun exposure: lentigo maligna melanoma subtype (OR = 3.2 vs. superficial spreading subtype), melanoma location on the head and neck (OR = 2.8 vs. back), histopathologic evidence of solar elastosis (OR = 2.1) and previous diagnosis of nonmelanoma skin cancer (OR = 2.4). Strong staining was negatively associated with high nevus density on the back (OR = 0.2 for >25 nevi vs. 0-3 nevi) and histologic evidence of a coexisting nevus (OR = 0.3). Other factors associated with strong p53 immunostaining include greater Breslow thickness (OR = 7.4 for >4.00 vs. <0.76 mm), male sex (OR = 2.2) and dense freckling (OR = 6.6 vs. few freckles). Of these, thickness, male sex, dense freckling, low nevus density on the back, histologic subtype and history of nonmelanoma skin cancer appeared to be independently associated with strong p53 staining. Our findings are consistent with the Queensland study in suggesting that variables indicating high accumulated sun exposure are positively associated with p53 staining and that an increased number of nevi is positively associated with its absence; they may reflect etiologic and pathogenetic heterogeneity in melanoma.

Atypical lentiginous junctional naevi of the elderly and melanoma

The diagnosis of atypical lentiginous melanocytic naevi in chronic sun-damaged skin is a clinical and pathological challenge. Mottled skin in the elderly is a result of extensive freckling, guttate hypomelanosis, solar lentigines, seborrhoeic keratoses and small dark lentigines. In addition, atypical lentiginous junctional naevi may be seen as isolated lesions and may merge with lesions that are indistinguishable from lentigo maligna. The predominant site distribution of such lesions on the trunk and limbs and the presence of a nested naevoid pattern on biopsy differs from classical lentigo maligna, which develops mainly on the head and neck. Based on case studies combining dermatoscopy with clinical and pathological features, we have found that atypical lentiginous junctional naevi of the elderly may evolve to lentigo maligna and in some cases to small cell (naevoid) melanomas. Such lesions have been previously classified as dysplastic naevi, atypical melanocytic hyperplasia, atypical melanocytic proliferation, atypical lentiginous melanocytic proliferation or premalignant melanosis (McGovern). The current definition of lentigo maligna appears too narrow and the pathway to lentigo maligna in the elderly skin may include a naevoid subset.

Improvement of early recognition of lentigo maligna using dermatoscopy

BACKGROUND

The clinical differentiation between lentigo senilis/initial seborrheic keratosis and lentigo maligna on the face can be difficult.

OBJECTIVE

Our purpose was to determine whether dermatoscopy (eg, skin surface microscopy at 10x magnification) can reliably differentiate between these entities.

METHODS

Dermatoscopic slides of 87 consecutive patients presenting 37 malignant and 50 benign pigmented skin lesions on the face were analyzed with the use of 27 dermatoscopic criteria.

RESULTS

Univariate analysis selected two criteria specific for lentigo maligna: asymmetric pigmented follicular openings and dark (brown or black) rhomboidal structures. Location-specific importance in relation to facial location was attributed to the color "slate-gray, " especially in combination with structures such as dots, globules, streaks, and homogeneous areas. Multivariate analysis (logistic regression model) revealed the 4 most important features to be asymmetric pigmented follicular openings, dark rhomboidal structures, slate-gray globules, and slate-gray dots with a sensitivity of 89% and a specificity of 96%.

CONCLUSION

Three conclusions can be drawn from our study: With a set of 4 dermatoscopic features, early lentigo maligna can be detected with high accuracy; dermatoscopic features on the face differ from criteria used in other locations; and our progression growth model for lentigo maligna delineates the different steps of malignant growth in lentigo maligna.

Malignant Melanomas Treated By Plastic Surgeons in Hamilton, Ontario: A Retrospective Study of 80 Patients with Clinical and Histological Correlation

The present retrospective study was designed to analyze the clinical and survival data of 80 patients diagnosed between 1969 and 1987 with confirmed invasive malignant melanoma in Hamilton, Ontario and surrounding region. The age of peak incidence was 31 to 40 years of age for men and 51 to 60 years of age for women. The most frequent type of melanoma was superficial spreading. The most frequent sites were the upper back, ankle and leg. The six-year survival rate for all the patients was 63%. Patients below 50 years of age had a significantly better survival rate than patients above 50 years of age. Survival appears to be inversely proportional to tumour thickness. The findings in this study are similar to those of previous studies regarding clinical features and prognosis. Patient age, and tumour histology and thickness remain important prognostic factors in determining survival for invasive malignant melanoma.

Benign melanocytic lesions: risk markers or precursors of cutaneous melanoma?

BACKGROUND

The role of benign melanocytic lesions as precursors and not only as risk markers for the development of cutaneous melanoma is controversial.

OBJECTIVE

The purpose of the study was to assess the frequency of the histologic association of benign melanocytic lesions with cutaneous melanoma of a maximum thickness of 1.00 mm. The possibility that the spatial association of benign lesions with melanoma may be coincidental was also investigated.

METHODS

The study subjects representing 289 cases of cutaneous melanoma of maximum thickness 1.00 mm (or less) were examined histologically for the presence of an associated benign melanocytic lesion(s), including lentiginous melanocytic proliferation; junctional, compound, or intradermal nevus; dysplastic nevus; and congenital nevus contiguous with or adjacent to the melanoma. The effects of age, tumor thickness, level of invasion, histologic type, and anatomic site on the association of benign melanocytic lesions with melanoma were assessed. In the control subjects 40 basal cell carcinomas and 38 compound nevi (not dysplastic) randomly chosen and matched for age (+/- 1 year) and site (head/neck, trunk, upper and lower limbs) with a melanoma case were examined to assess the proportion of these cases associated with benign lesions compared with the matched melanoma cases.

RESULTS

A nevus was associated with melanoma in 51% of cases (n = 147). Of these, 82 (56%) were dysplastic nevi, 61 (41%) were common acquired nevi, and 4 (3%) were congenital nevi. Lentiginous melanocytic proliferation was present in the epidermis adjacent to 219 melanomas (75%) and in 44% of these cases (n = 97) a coexisting nevus was also present.

CONCLUSION

The results of this study lend further support to the concept of common acquired nevi and dysplastic nevi as precursors of cutaneous melanoma. In addition, lesions diagnosed clinically as simple lentigo and solar lentigo may be important as potential precursors of melanoma, particularly in the elderly.

Skin cancer. Melanoma and other specific nonmelanoma skin cancers

BACKGROUND

Malignant melanoma accounts for most of the growing mortality from skin cancer. However, survival rates are increasing for individual cases, probably because of earlier diagnoses.

METHODS

Skin cancers collected by the SEER population-based data base between 1973 and 1987 are described in terms of their histologic classification and their distribution by sex, race, anatomical location, geographic locality, and time period of occurrence.

RESULTS

There were 30,519 invasive skin cancers in the 15-year reporting period. Because the common basal cell and squamous cell cancers are not reportable to SEER, most of the cancers (28,206) were melanomas. In addition, 4386 in situ melanomas were reported. The rate of melanoma was 13-fold higher in whites than in blacks and 29% higher in white males than in white females. There was a 52% increase in the age-adjusted incidence rate for invasive melanoma and a 600% increase in the incidence rate of in situ melanoma over the 15-year period for whites and a 12% decrease in the incidence rate of invasive melanoma in blacks. The incidence of melanoma in the ear and trunk predominated in males, whereas melanoma of the lower limb predominated in females. Incidence rates and rate of increase of incidence of melanoma varied by anatomical subsite, sex, and geographic location within the United States.

CONCLUSIONS

The variations among incidence rates of melanoma by sex, subsite, race, geographic location, and time period support prevailing theories of a solar cause for most but not all cases of this disease. Although melanoma rates are rising overall, the disproportionate rise in the rate of diagnosis of in situ compared with invasive melanoma suggests that melanomas are being diagnosed earlier.

Excess melanocytic nevi in children with renal allografts

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 effects of surgical treatment on survival and local recurrence of cutaneous malignant melanoma

All patients with a diagnosis of cutaneous malignant melanoma (CMM) in Western Australia from 1980 to 1981 were observed for up to 6 years to determine vital status and to detect the development of local recurrences of the primary lesion. Approximately 35% of all patients had their tumors excised with surgical margins of less than 1 cm. When compared with patients whose tumors were excised with margins of at least 2 cm, the fatality rate in those with narrow margins was slightly less (rate ratio, 0.60; 95% confidence interval [CI], 0.20% to 1.80% for margins of 5 to 9 mm; rate ratio, 0.69; 95% CI, 0.26% to 1.87% for margins of 1 to 4 mm); however, this difference could have been caused by chance alone. The risk of local recurrence within 5 years after diagnosis was 2% (95% CI, 1% to 4%). The risk was strongly related to age and tumor thickness, but did not appear to be influenced by the width of excision (greater than 1 cm versus less than 1 cm: rate ratio, 1.03; 95% CI, 0.25% to 4.34%). The apparent lack of effect could be caused by to chance alone because the number of local recurrences was small.

Survival among patients with clinical stage I cutaneous malignant melanoma diagnosed in Western Australia in 1975/1976 and 1980/1981

Five-year survival rates were slightly higher for patients with cutaneous malignant melanoma (CMM) diagnosed in Western Australia in 1980/1981 (89% in men and 95% in women) than in those whose melanomas were diagnosed in 1975/1976 (88% in men and 91% in women). The improvement in survival was probably due to a decrease in median tumor thickness from 1.29 mm in 1975/1976 to 0.77 mm in 1980/1981 because tumor thickness was the most important histologic index of prognosis. Tumor cell type and cross-sectional profile were the only other histologic characteristics that independently influenced fatality rates. Prognosis was significantly worse in males than in females and in patients with tumors on the posterior head and neck. Ten-year survival rates of patients whose melanomas were diagnosed in 1975/1976 was 82% in men and 87% in women, indicating that these patients continued to experience some excess mortality up to 10 years after diagnosis. The comparatively small improvement in prognosis in the 5-year period between these two groups suggests that survival might be expected to continue to improve only gradually unless there is a sharp absolute decrease in the number of thick tumors diagnosed.

Descriptive epidemiology of skin cancer in the Swiss Canton of Vaud

Incidence registration and survival data for non-melanocytic skin neoplasms and cutaneous melanoma have been abstracted from the population-based system of the Cancer Registry of the Swiss Canton of Vaud, which has been operating in a particularly favourable environment, since the large majority of cutaneous lesions resected in the area are examined by a pathologist. Among the 5,712 cases registered, 66.7% were basal-cell carcinomas, 20.6% squamous-cell cancers, 9.3% cutaneous melanomas and 3.4% other miscellaneous histological types. The distribution by histological type did not differ appreciably in the 2 sexes, but there were marked inter-sex differences as regards anatomical site. In both sexes, head and neck was by far the commonest localization for non-melanomatous neoplasms (69 to 81% of all incident cases), followed by trunk for basal-cell cancers (18% in males, 15% in females) and upper limb for squamous-cell (10% in males, 17% in females). The distribution of skin melanomas differed considerably between the 2 sexes, by far the commonest site being the trunk for males (45% of cases) and lower limbs for females (40%), followed by head and neck (22% in both sexes). Incidence rates for both basal- and squamous-cell cancers increased with age, and rates were higher in males for each localization except the lower limb. In contrast, incidence for melanoma was higher in females, and incidence rates did not increase with age above 55 years for all sites except head and neck. This can be interpreted in terms of cohort effect, since mortality from melanoma has substantially increased in Switzerland across subsequent birth cohorts. Although this study is essentially descriptive, accurate inspection of these data provides some support for the major aetiological hypotheses of skin carcinogenesis, i.e., the observation that the large majority of basal- and squamous-cell cancers arise on the head and neck confirms the importance of long-term ultraviolet exposure; the relative excess of squamous-cell as compared to basal-cell neoplasms on the upper limb may suggest the role of exposure to other (chemical) carcinogens; and the proportional excess of melanomas on the trunk in males and lower limb in females further indicates that intermittent exposure to sunlight is probably the relevant aetiologic factor for melanocytic skin neoplasms.