Faculty Bibliography

A multivariate analysis was performed on 20 clinical and histologic variables from 327 Stage I prospectively studied melanoma patients who underwent elective regional lymph node dissection (ERLD). Primary tumor thickness, microscopic satellites, and the elapsed interval between diagnosis and ERLD, were selected as the combination of variables that were most highly associated with clinically occult regional lymph node metastases (P = 10(-15), model chi-square). Microscopic satellites were defined as tumor nests, greater than 0.05 mm in diameter, in the reticular dermis, panniculus, or vessels beneath the principal invasive tumor mass but separated from it by normal tissue on the section in which the Breslow measurement was taken. The probability of finding nodal metastases for melanomas less than 0.75 mm thick was 0% (0/41 patients); for those 0.76-1.50 mm, 4% (4/108); 1.51-3.0 mm, 14% (14/102); and greater than 3.0 mm, 39.5% (30/76). Primary melanomas greater than 1.50 mm thick with microscopic satellites were more often associated with nodal metastases than those of similar thickness without satellites (30/57 (53%) versus 14/121 (12%), P = 0.01). Some satellites probably represent intraspecimen metastases, while others do not. Any predictive model for occult regional lymph node metastases based on data from ERLD done less than 50 days after diagnosis may underestimate the prevalence of metastases

In an attempt to determine whether exposure to fluorescent lights may cause an increased risk for developing melanoma, 114 patients with melanoma were compared to 228 age-matched controls. Fluorescent-light exposure, along with 10 other risk factors, was analyzed for its possible relationship to malignant melanoma. No association was found between fluorescent-light exposure and increased risk for acquiring malignant melanoma

A study of the influence of the anatomical location of malignant melanoma on the prognosis of 971 patients with stage I disease disclosed specific high-, intermediate-, and low-risk sites. High-risk sites included scalp, mandibular area, midline of trunk (anterior and posterior), upper medial thighs, hands, feet (except the arches), popliteal fossae, and genitalia. The life-table-adjusted five-year disease-free survival was 54% in the high-risk locations, 79% in intermediate-risk locations, and 93% in low-risk sites. A Cox proportional hazards analysis demonstrated that the grouping of lesions by their anatomical risk location had prognostic value that was significant in a model of eight other known predictive variables (thickness, sex, age, type, level, mitotic index, ulceration, and presence of preexistent nevus). The results indicate that anatomical location of the primary melanoma is significantly associated with five-year disease-free survival

A total of 672 consecutive patients with clinical stage I and stage II primary cutaneous malignant melanoma were treated by excision of 3.0 to 5.0 cm of surrounding skin down to and including the underlying fascia when the lesion exceeded 0.5 mm thickness (Breslow measurement). More conservative margins were taken in locations where such excisions would result in significant cosmetic or functional morbidity and for thinner lesions (less than 0.5 mm). Seven of 658 patients with clinical stage I disease (1.1%) and three of 14 patients with clinical stage II disease (21.4%) developed histologically verified local metastases within 5 cm of the primary excision scar or skin graft. Fifteen patients with stage I disease developed in-transit metastases (2.3%) at a site more than 5.0 cm proximal to the surgical scar or skin graft but not beyond the regional nodal group. Two patients with stage II disease who had developed local metastases also developed in-transit metastases (14.3%). No patient with a lesion less than 1.0 mm thick has had a local recurrence. Nine of the ten patients (90%) who developed local metastases and 12 of the 17 patients (70.6%) who developed in-transit metastases have also developed systemic metastases to date. Local and in-transit metastases following such definitive excision is a significant indicator of disseminated systemic metastatic melanoma

In a clinicohistopathologic study of 557 patients with primary cutaneous malignant melanoma, there were fewer metastases and/or deaths from melanoma when histologic evidence of a coexisting acquired melanocytic nevus was found. A total of 130 patients with melanocytic nevus and 427 cases of melanoma without histologic evidence of a nevus (denovo) were studied. Clinical follow-up evaluation for evidence of metastases and/or death was obtained. Only ten of the patients (7.7%) with nevus-associated melanoma had metastases and/or death v 78 (18.3%) with de novo melanoma. When stratified by lesion thickness, the logrank test for survival revealed a statistically significant difference between the two groups. An overall favorable outcome seen in patients with malignant melanomas associated with acquired melanocytic nevi was found, therefore, to be independent of lesion thickness as well as six other variables reported to be related to the biologic behavior of malignant melanoma. Thus, the presence of nevus cells in a specimen of malignant melanoma portends a better prognosis and may have important implications in the biology of this neoplasm

A multiple stepwise logistic regression analysis shows that histologic regression is more likely to be found in a malignant melanoma that is level III or less, more than 10 mm in diameter, associated with solar elastosis, located on an anatomic area other than the head or neck, and when there are areas of whiteness clinically. Although patients with malignant melanomas displaying signs of regression histologically have a slightly better 5-year disease-free survival, this may be attributed to a difference in tumor thickness

Although thin malignant melanomas, i.e., those less than 0.76 mm in thickness, of the skin generally do not metastasize, it has been recently reported that when histologic regression is present, such lesions may then have a greater propensity for dissemination. However, this was not apparent in this study in which only one melanoma metastasized in a consecutive series of 41 thin lesions which were step-sectioned and had evidence of regression histologically. Possible explanations for this discrepancy are the failure of other authors to include only step-sectioned specimens of the primary melanomas in their material and/or geographic differences in the biologic behavior of this malignant neoplasm