Lingual juvenile xanthogranuloma in a woman: a case report

<p>Abstract</p> <p>Introduction</p> <p>Juvenile xanthogranuloma is a rare non-Langerhans cell histiocytosis that usually occurs during infancy and early childhood. The presence of single or multiple raised cutaneous lesions characterize this self-healing disorder. Extracutaneous sites are rare.</p> <p>Case presentation</p> <p>We present a rare case of oral juvenile xanthogranuloma in a 49-year-old Caucasian woman. The histopathologic diagnosis of the lingual neoformation was histiocitary proliferation with the presence of giant cells, Touton type, compatible with juvenile xanthogranuloma.</p> <p>Conclusion</p> <p>To establish an accurate diagnosis, microscopic evaluation and immunohistochemical staining are necessary. Dentists, dermatologists and general practitioners may be the first to recognize this rare condition during the inspection of the oral cavity.</p

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

MAP Kinase Pathways: Molecular Roads to Primary Acral Lentiginous Melanoma

Freitas, Luiz Antônio Rodrigues de “Documento produzido em parceria ou por autor vinculado à Fiocruz, mas não consta à informação no documento”.Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2017-07-12T16:30:58Z No. of bitstreams: 1 Fernandes JD MAP kinase pathways.pdf: 410090 bytes, checksum: 9dd1732a2a2b04a3e40d25b66810022d (MD5)Approved for entry into archive by Ana Maria Fiscina Sampaio ([email protected]) on 2017-07-12T16:51:53Z (GMT) No. of bitstreams: 1 Fernandes JD MAP kinase pathways.pdf: 410090 bytes, checksum: 9dd1732a2a2b04a3e40d25b66810022d (MD5)Made available in DSpace on 2017-07-12T16:51:53Z (GMT). No. of bitstreams: 1 Fernandes JD MAP kinase pathways.pdf: 410090 bytes, checksum: 9dd1732a2a2b04a3e40d25b66810022d (MD5) Previous issue date: 2015Federal University of Bahia. Medical School. Department of Dermatology. Salvador, BA, BrazilUniversity of São Paulo. Dental School. Department of General Pathology. São Paulo, SP, BrazilFederal University of Bahia. Medical School. Department of Pathology. Salvador, BA, BrazilAMO. Oncological Clinic Care. Salvador, BA, BrazilUniversity of São Paulo. Dental School. Department of General Pathology. São Paulo, SP, Brazil / University of São Paulo. Medical School. Department of Dermatology. São Paulo, SP, BrazilHospital Obrero. Department of Surgical Pathology. La Paz, BoliviaUniversity of São Paulo. Medical School. Department of Dermatology. São Paulo, SP, BrazilThe etiology and pathogenesis of lentiginous acral melanomas are poorly understood. Recent studies have postulated that DNA repair mechanisms and cell growth pathways are involved in the development of melanoma, particularly changes in the MAPK pathways (RAS, BRAF, MEK 1/2, and ERK 1/2). The aim of this study is to assess the status of the MAP kinase pathways in the pathogenesis of acral melanomas. The authors examined the components of the RAS-RAF-MEK-ERK cascades by immunohistochemistry in a series of 16 primary acral melanomas by tissue microarray. The expression of MAP kinase cascade proteins changed in most cases. The authors observed that 57.14% of cases were BRAF positive and that 61.53%, 71.42%, and 71.42% of cases were positive for MEK2, ERK1, and ERK2, respectively; RAS was not expressed in 92.31%, and all cases were negative for MEK1. The absence of RAS and positivity for MEK2, ERK1, and ERK2 were most seen in invasive cases with high thickness. These aspects of the MAPK pathway require further examination in acral melanomas between different populations. Nevertheless, the results highlight significant alterations in the MAP kinase cascades that are related to histological indicators of prognosis in primary acral melanomas