Acral melanocytic lesions in the United States: Prevalence, awareness, and dermoscopic patterns in skin-of-color and non-Hispanic white patients.

BACKGROUND: Acral lentiginous melanoma has increased mortality compared with other melanoma subtypes and disproportionately affects ethnic minorities. Acral melanocytic lesions have not been well studied in diverse populations of the United States. OBJECTIVE: We sought to assess the prevalence, awareness, and dermoscopic patterns of acral melanocytic lesions in skin-of-color and non-Hispanic white patients. METHODS: We prospectively examined the palms and soles of 1052 patients presenting to dermatology clinics in New York, NY, and Miami, FL, from October 2013 to April 2015. RESULTS: Acral melanocytic lesions were observed in 36% of our cohort. Skin-of-color patients were more likely to have acral melanocytic lesions than non-Hispanic white patients (P < .01). Acral melanocytic lesions correlated with increased mole counts, particularly on non-Hispanic white patients. The majority of lesions demonstrated benign dermoscopic patterns. We observed 2 lesions with the parallel ridge pattern in our cohort, both found to be atypical nevi on biopsy specimen. Patients often lacked awareness of the presence of their lesions. LIMITATIONS: Interobserver variability in assessing dermoscopic patterns is a limitation. CONCLUSIONS: Melanocytic lesions of the palms and soles are common, particularly in a cohort of multiple ethnicities from the United States. Dermoscopy of acral lesions is an important clinical tool for diagnosis and management of these lesions.

Ultra-High-Frequency Reprogramming of Individual Long-Term Hematopoietic Stem Cells Yields Low Somatic Variant Induced Pluripotent Stem Cells.

Efficiency of reprogramming of human cells into induced pluripotent stem cells (iPSCs) has remained low. We report that individual adult human CD49f+ long-term hematopoietic stem cells (LT-HSCs) can be reprogrammed into iPSCs at close to 50% efficiency using Sendai virus transduction. This exquisite sensitivity to reprogramming is specific to LT-HSCs, since it progressively decreases in committed progenitors. LT-HSC reprogramming can follow multiple paths and is most efficient when transduction is performed after the cells have exited G0. Sequencing of 75 paired skin fibroblasts/LT-HSC samples collected from nine individuals revealed that LT-HSCs contain a lower load of somatic single-nucleotide variants (SNVs) and indels than skin fibroblasts and accumulate about 12 SNVs/year. Mutation analysis revealed that LT-HSCs and fibroblasts have very different somatic mutation signatures and that somatic mutations in iPSCs generally exist prior to reprogramming. LT-HSCs may become the preferred cell source for the production of clinical-grade iPSCs.

Ultraviolet radiation and melanoma.

Melanoma is a particularly aggressive type of skin cancer, and its incidence has been increasing steadily since the 1970s. This article will review the extensive epidemiologic data demonstrating that ultraviolet radiation (UVR) exposure, from the sun or artificial tanning beds, is the most important environmental risk factor for melanoma; the multiple detrimental effects of UVR on human skin, including DNA damage through the formation of dimeric photoproducts, gene mutations, oxidative stress, inflammation, and immunosuppression, all of which contribute to melanomagenesis; and the evidence that protection from UVR exposure, whether by melanin or by sunscreen, reduces the risk of developing melanoma.