RESUMO
Pheochromocytomas (PCCs) and paragangliomas (PGLs) are tumors arising from the adrenal medulla and sympathetic/parasympathetic paraganglia, respectively. Approximately 40% of PCCs/PGLs are due to germline mutations in one of 16 susceptibility genes, and a further 30% are due to somatic alterations in 5 main genes. Recently, somatic ATRX mutations have been found in succinate dehydrogenase (SDH)-associated hereditary PCCs/PGLs. In the present study we applied whole-exome sequencing to the germline and tumor DNA of a patient with metastatic composite PCC and no alterations in known PCC/PGL susceptibility genes. A somatic loss-of-function mutation affecting ATRX was identified in tumor DNA. Transcriptional profiling analysis classified the tumor within cluster 2 of PCCs/PGLs (without SDH gene mutations) and identified downregulation of genes involved in neuronal development and homeostasis (NLGN4, CD99 and CSF2RA) as well as upregulation of Drosha, an important gene involved in miRNA and rRNA processing. CpG island methylator phenotype typical of SDH gene-mutated tumors was ruled out, and SNP array data revealed a unique profile of gains and losses. Finally, we demonstrated the presence of alternative lengthening of telomeres in the tumor, probably associated with the failure of ATRX functions. In conclusion, somatic variants affecting ATRX may play a driver role in sporadic PCC/PGL.
Assuntos
Neoplasias das Glândulas Suprarrenais/genética , DNA Helicases/genética , Proteínas Nucleares/genética , Feocromocitoma/genética , Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Idoso , DNA Helicases/metabolismo , Análise Mutacional de DNA , Exoma , Perfilação da Expressão Gênica , Humanos , Masculino , Mutação , Proteínas Nucleares/metabolismo , Feocromocitoma/diagnóstico por imagem , Análise de Sequência de Proteína , Homeostase do Telômero/genética , Proteína Nuclear Ligada ao XRESUMO
Papular epidermal nevus with "skyline" basal cell layer (PENS), a variant of epidermal nevus, was recently described in otherwise normal children. We describe herein a patient with multiple, typical PENS lesions associated with peculiar facies, bilateral Achilles tendon shortening, and mild psychomotor delay. The association of PENS with extracutaneous manifestations suggests the possibility of a new type of epidermal nevus syndrome, for which we propose the term PENS syndrome.
Assuntos
Tendão do Calcâneo/anormalidades , Epiderme/patologia , Fácies , Nevo Pigmentado/diagnóstico , Transtornos Psicomotores/diagnóstico , Neoplasias Cutâneas/diagnóstico , Adolescente , Humanos , Masculino , Nevo , Síndrome , Terminologia como AssuntoRESUMO
Mantle cell lymphoma is routinely considered as a Bcl6-negative B-cell lymphoma carrying the translocation t(11;14). Here we describe a series of five Bcl6-positive mantle cell lymphoma cases, including three classic and two blastoid variants. The proliferative index of these cases, measured with the Ki-67 antibody, was slightly higher than in Bcl6-negative mantle cell lymphoma cases (32.2 vs. 23.7%) Bcl6 expression was associated with translocations involving 3q27 in four of the five cases and an extra copy of the BCL6 gene in the fifth. A mutational study of the major mutational cluster in the BCL6 gene revealed no increased mutation rate, except in one case. One of the three cases displayed a high mutational index in the IgVH gene, suggesting exposure to a germinal center microenvironment. Chromosomal alterations involving 3q27 seem to be responsible for this increased Bcl6 expression, which needs to be considered when Bcl6 is used in lymphoma diagnosis.