- 9 例典型真皮神经鞘黏液瘤：四肢多结节黏液性病变，梭形/上皮样细胞网状索条 + 印戒样空泡细胞；弥漫 S100/SOX10/GFAP。
- RNA 测序 7/9 检出相同框内 DPYSL2::CDX1 融合；FISH（分离+双融合）6/7 证实——该瘤种首个反复分子改变。
- 支持 DNSM 作为独立实体，并为形态困难病例提供分子辅助；扩展 CDX1 重排软组织肿瘤谱系。
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收录范围：PubMed 英文摘要及中文翻译（abstract-only）。Unpaywall 显示 hybrid OA（CC BY），但 modernpathology.org / ScienceDirect 从本站出口遇 Cloudflare challenge，未取得全文与图表。
摘要
真皮神经鞘黏液瘤（dermal nerve sheath myxoma，DNSM）是一种少见的良性间叶性肿瘤，推定向神经鞘分化，具有独特的形态与免疫表型特征，但其分子发病机制仍不清楚。我们研究了 9 例形态典型的 DNSM，并进行分子检测以寻找反复遗传学改变。队列包括女 5 例、男 4 例（中位年龄 56 岁；范围 23–75 岁）。肿瘤多发生于四肢，表现为多结节状、真皮为主的黏液性肿瘤，由均一的梭形至上皮样细胞在丰富黏液基质中呈网状索条排列。所有肿瘤均可见空泡状「印戒样」细胞。免疫组化方面，所有检测肿瘤均弥漫表达 S100、SOX10 与 GFAP，部分局灶表达 EMA、角蛋白 AE1/AE3 与 GLUT1。基于 RNA 的测序在 9 例中的 7 例检出相同的框内 DPYSL2::CDX1 融合。用 CDX1、DPYSL2 分离探针及 DPYSL2/CDX1 双融合探针的荧光原位杂交在 7 例受检肿瘤中的 6 例证实重排。我们据此表明，多数 DNSM 以反复 DPYSL2::CDX1 融合为特征，这是该瘤种首次确认的反复分子改变。这些发现进一步支持将 DNSM 归为独立肿瘤实体，并凸显分子检测在形态困难病例中作为诊断辅助的潜在价值。CDX1 相关融合的生物学作用及其与其他融合驱动软组织肿瘤（尤其带 CDX1/CDX2 融合者）的关系，有待进一步研究。
- Nine classic dermal nerve sheath myxomas: multinodular myxoid extremity tumours with reticular cords of spindled/epithelioid cells and signet-ring-like vacuolated cells; diffuse S100/SOX10/GFAP.
- Identical in-frame DPYSL2::CDX1 fusion in 7/9 by RNA sequencing; FISH confirmed rearrangement in 6/7 — first recurrent molecular alteration in DNSM.
- Supports DNSM as a distinct entity and a diagnostic adjunct in morphologically challenging cases; expands the CDX1-rearranged soft-tissue spectrum.
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Scope: PubMed abstract only. Unpaywall lists hybrid OA (CC BY), but modernpathology.org / ScienceDirect returned Cloudflare challenges from this egress; full text and figures were not collected.
Abstract
Dermal nerve sheath myxoma (DNSM) is a rare benign mesenchymal tumor with presumed nerve sheath differentiation with distinctive morphologic and immunophenotypic features; however, its molecular pathogenesis remains poorly understood. We investigated a series of nine morphologically classic DNSMs and performed molecular testing to identify recurrent genetic alterations. The cohort included five female and four male patients (median age: 56 years; range: 23-75 years). Tumors arose predominantly on the extremities and presented as multinodular dermal-based myxoid neoplasms composed of uniform spindled to epithelioid cells arranged in reticular cords within abundant myxoid stroma. Vacuolated "signet ring-like" cells were identified in all tumors. Immunohistochemically, all tested tumors showed diffuse S100, SOX10 and GFAP expression, and a subset focally expressed EMA, keratin AE1/AE3, and GLUT1. RNA-based sequencing identified an identical in-frame DPYSL2::CDX1 fusion in 7 of 9 cases. Fluorescence in situ hybridization testing using CDX1 and DPYSL2 break apart probes as well as DPYSL2/CDX1 dual-fusion probe confirmed rearrangement in 6/7 tested tumors. We herein demonstrate that most DNSM are characterized by recurrent DPYSL2::CDX1 fusions, representing the first recurrent molecular alteration identified in this tumor type. These findings further support the classification of DNSM as a distinct neoplastic entity and highlight the potential utility of molecular testing as a diagnostic adjunct in morphologically challenging cases. Further studies are warranted to clarify the biologic role of CDX1-related fusions and their relationship to other fusion-driven soft tissue neoplasms, particularly those with CDX1/CDX2 fusions.