From the Department of Surgical Pathology, Sarah Network of Rehabilitation Hospitals, Brasília, DF, Brazil (ICSB, FSdS); Department of Neurosurgery, Sarah Network of Rehabilitation Hospitals, Brasília, DF, Brazil (RdAG, MdMC); Department of Imaging, Sarah Network of Rehabilitation Hospitals, Brasília, DF, Brazil (BJAFM); Department of Orthopedics, Sarah Network of Rehabilitation Hospitals, Brasília, DF, Brazil (CS); Department of Pathology, AC Camargo Cancer Center Rua Tamandaré, São Paulo, SP, Brazil (IWdC, RKK).
J Neuropathol Exp Neurol. 2021 Nov 19;80(11):1068–1077. doi: 10.1093/jnen/nlab106. Epub 2021 Oct 30.
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 β-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.
神经肌肉嵴瘤（NMC）是一种外周神经系统病变，其特征为混杂有骨骼肌纤维和神经束。NMC 常与韧带样纤维瘤病（DF）有关。CTNNB1 基因（β-连环蛋白蛋白基因）的突变在 DF 中很常见，与其发病机制有关。这些突变仅限于外显子 3，有 3 种点突变：T41A、S45F 和 S45P。为了了解 NMC 的发病机制，我们检测了 5 例 NMC 中 CTNNB1 状态，无论它们是否与 DF 有关。CTNNB1 基因突变的筛选是基于使用 ION Proton 平台的扩增子深度测序。3 例患者有 S45F 突变；2 例在两种病变中均有突变，1 例 DF 为野生型，而 NMC 有 S45F 突变。1 例 NMC 有 T41A 突变，无相关 DF。在最后 1 例患者中，DF 病变有 T41A 突变；无 S45P 突变的病变。在 NMC/DF 相关病变和散发性 DF 中存在类似的 CTNNB1 突变，这加强了两种病变之间的关系，并指出了共同的发病机制。
