Characteristics and survival of patients with invasive amelanotic melanoma in the USA :

Reduced melanoma mortality should result from an improved understanding of modifiable factors related to early detection. The authors of this report surveyed newly diagnosed patients to identify differences in prediagnosis behavioral and medical care factors associated with thinner versus thicker melanoma. In total, 566 adults with invasive melanoma completed questionnaires within 3 months of diagnosis on demographics, health care access, skin self-examination (SSE), and physician skin examination (PSE) practices in the year before diagnosis. SSE was measured by us e of a melanoma picture aid and routine examination of some/all body sites versus none. Patient-reported partial or full-body PSE also was assessed. Melanoma thickness was dichotomized at 1 mm. Patient ranged in age from 18 years to 99 years, and 61% were men. The median tumor thickness was 1.25 mm, and 321 tumors (57%) were >1 mm thick. Thinner tumors (≤1 mm) were associated with age ≤60 years (P = .0002), women (P = .0127), higher education level (P = .0122), and physician discovery (P ≤ .0001). Patients who used a melanoma picture aid and performed routine SSE were more likely to have thinner tumors than those who did not (odds ratio [OR], 2.66; 95% confidence interval [CI], 1.48-4.80). Full-body PSE was associated with thinner tumors (OR, 2.51; 95% CI, 1.62-3.87), largely because of the effect of PSE in men aged >60 years (OR, 4.09 95% CI, 1.88-8.89). SSE and PSE were identified as complementary early detection strategies, particularly in men aged >60 years, in whom both partial and full-body PSE were associated with thinner tumors. Given the high rates of physician access, PSE may be a more practical approach for successful early detection in this subgroup with highest mortality. Copyright © 2011 American Cancer Society.

To gain insight into reducing melanoma mortality by examining epidemiologic trends by subtype with emphasis on the contribution of each subtype to melanoma-related death.

Amelanotic melanoma can have a varied appearance both clinically and microscopically. Here, we present our experiences with 75 cases of amelanotic melanoma defined clinically as a non-pigmented lesion and histopathologically as a tumor lacking significant melanization. We evaluated microscopic features such as morphology, mitotic count, nuclear atypia and presence of solar elastosis. Our amelanotic melanomas exhibited the following morphology: epitheloid (72%), spindled (18.7%) or desmoplastic (5.3%). In addition, we obtained patient information and clinical presentations on most of the cases (74/75; 98.7%) and follow-up data on 40% (30/75) of the cases. The majority of amelanotic melanomas in men were found on the trunk (13/45; 29%), head and neck (12/45; 26.7%), and lower limb (13/45; 29%) and in women were found on the lower limb (12/30; 40%), upper limb (10/30; 33.3%) and head and neck (6/30; 20%). In addition, we found that an increase in mitotic index correlated with worse survival (p < 0.026), whereas there were no differences in survival for other pathological features, such as nuclear atypia or solar elastosis. Furthermore, in cases with available tissue, all amelanotic melanoma expressed microphthalmia-associated transcription factor and tyrosinase, suggesting that the tumor cells retained melanocytic lineage and an enzyme in melanin formation, respectively. As the occurrence of amelanotic melanoma and the expression melanoma markers were similar to pigmented melanoma, we favor that amelanotic melanoma represents a subtype of melanoma rather than poorly differentiated or de-differentiated melanoma.