The genetic evolution of acral melanoma.

Acral melanoma is an aggressive type of melanoma with unknown origins. It is the most common type of melanoma in individuals with dark skin and is notoriously challenging to treat. We examine exome sequencing data of 139 tissue samples, spanning different progression stages, from 37 patients. We find that 78.4% of the melanomas display clustered copy number transitions with focal amplifications, recurring predominantly on chromosomes 5, 11, 12, and 22. These complex genomic aberrations are typically shared across all progression stages of individual patients. TERT activating alterations also arise early, whereas MAP-kinase pathway mutations appear later, an inverted order compared to the canonical evolution. The punctuated formation of complex aberrations and early TERT activation suggest a unique mutational mechanism that initiates acral melanoma. The marked intratumoral heterogeneity, especially concerning MAP-kinase pathway mutations, may partly explain the limited success of therapies for this melanoma subtype.

Epstein-Barr virus and skin

Abstract: Epstein-Barr virus is a DNA virus infecting human beings and could affect 90% of human population. It is crucial to take in account that in Latin America, unlike what happens in developed countries, the exposure to the virus is very early and therefore people have a much longer interaction with the virus. The virus is related to many diseases, mainly the oncological ones, and when the onset is in cutaneous tissue, it can present many clinical variants, as well acute as chronic ones. Among the acute ones are infectious mononucleosis rash and Lipschutz ulcers; the chronic presentations are hypersensivity to mosquito bites, hydroa vacciniforme, hydroa vacciniforme-like lymphoma, its atypical variants and finally nasal and extra-nasal NK/T-cell lymphoma. Although they are not frequent conditions, it is crucial for the dermatologist to know them in order to achieve a correct diagnosis.

Epstein-Barr virus and skin.

Epstein-Barr virus is a DNA virus infecting human beings and could affect 90% of human population. It is crucial to take in account that in Latin America, unlike what happens in developed countries, the exposure to the virus is very early and therefore people have a much longer interaction with the virus. The virus is related to many diseases, mainly the oncological ones, and when the onset is in cutaneous tissue, it can present many clinical variants, as well acute as chronic ones. Among the acute ones are infectious mononucleosis rash and Lipschutz ulcers; the chronic presentations are hypersensivity to mosquito bites, hydroa vacciniforme, hydroa vacciniforme-like lymphoma, its atypical variants and finally nasal and extra-nasal NK/T-cell lymphoma. Although they are not frequent conditions, it is crucial for the dermatologist to know them in order to achieve a correct diagnosis.

Dermatitis Herpetiforme: a propósito de una caso / Herpetiformis dermatitis: about a case

La dermatitis herpetiforme es una enfermedad ampollosa autoinmune poco frecuente. Las lesiones cutáneas son polímorfas y el estudio histopatológico es inespecífico en un porcentaje elevado de casos, por ello su diagnóstico puede ser dificil si no se realizan las pruebas complementarias pertinentes. Se considera la manifestación cutánea de una enteropatía por sensibilidad al gluten, asintomática en un elevado número de casos. Frecuentemente se asocia a otras enfermedades autoinmunes y existe riesgo de desarrollo de linforma no Hodgkin de células T a nivel intestinal. Su diagnóstico se basa en la clínca, pruebas tísulares (histopatología e inmunofluorescencia directa) y serológicas (anticuerpos anti-endomisio, anti-trasglutaminasa tísular y anti-gtrasglutaminasa epidermica). La base del tratamiento es la dieta sin gluten estricta que debe instaurarse precozmente con la finalidad de evitar complicaciones posteriores y mantenerse de por vida. La dapsona y otros fármacos son útiles para inducir la remisión de los síntomas cutáneos hasta el inicio del efecto de la dieta.