Neuromuscular Choristoma: Report of Five Cases With CTNNB1 Sequencing.

Neuromuscular choristoma (NMC) are lesions of the peripheral nervous system characterized by an admixture of skeletal muscle fibers and nerves fascicles that are frequently associated with desmoid fibromatosis (DF). Mutations in CTNNB1, the gene for ß-catenin protein, are common in DF and related to its pathogenesis. They are restricted to exon 3, with 3 point mutations: T41A, S45F, and S45P. To understand the pathogenesis of NMC, we tested CTNNB1 status in 5 cases of NMC whether or not they were associated with DF. The screening of mutations in CTNNB1 gene was based on amplicon deep sequencing using the ION Proton platform. Three patients had the S45F mutation; in 2 the mutation was common to both lesions and in one the DF was wild type while the NMC had the S45F mutation. One patient had a T41A mutation in the NMC and no associated DF. In the last patient, the DF lesion had a T41A mutation; there was no lesion with the S45P mutation. The presence of similar CTNNB1 mutations in NMC/DF-associated lesions and sporadic DF reinforces the relationship between both lesions and points to a common pathogenic mechanism.

Carcinoma neuroendócrino cutâneo primário (Ca de Merkel): relato de 6 casos e revisäo da literatura / Cutaneous primary neuroendocrine carcinoma (Ca de Merkel): report of 6 case and review of literature

Os autores apresentam seis casos de carcinoma neuroendócrino primário cutâneo tratados na INCa-RJ no período de janeiro/1980 a dezembro/1993 e confirmados pela imunohistoquímica. O trabalho enfatiza a necessidade de confirmaçäo diagnóstica pelo uso deste método além de recomendar tratamento radical baseado na ressecçäo cirúrgica ampla acompanhada por esvaziamento linfático regional eletivo que poderá ser complementado ou näo pela radioterapia e ou pela quimioterapia.