Scholarlink

<p>Astroblastoma, <i>MN1</i>-altered, is a rare circumscribed glial neoplasm defined by alterations in the <i>MN1</i> gene and often the <i>MN1::BEND2</i> fusion. However, it is noted that a subset of these tumors lacks the classic astroblastic perivascular pseudorosettes, which can complicate diagnosis. We report a diagnostically challenging case in a 6-year-old female presenting with gait disturbance and limb weakness. MRI identified a well-defined fourth ventricular roof mass causing obstructive hydrocephalus. Histology post-resection revealed a solid tumor composed of epithelioid cells arranged in sheets and nests, exhibiting abundant cytoplasm, nuclear atypia, and prominent grooves, but no astroblastic pseudorosettes or significant mitosis. Immunohistochemically, tumor cells were negative for GFAP and Olig2, showed only focal EMA expression, but exhibited diffuse PR positivity. Methylation profiling did not match any established WHO CNS5 subtype, while targeted NGS identified a defining <i>TCF3::BEND2</i> in-frame fusion. This case supports the existence of a phenotypically distinct variant within the spectrum of <i>BEND2</i>-rearranged neuroepithelial tumors, characterized by the <i>TCF3::BEND2</i> fusion. Although molecularly related to <i>MN1</i>-altered astroblastoma, it displays distinct histological and immunophenotypic features. These findings further support the role of <i>BEND2</i> as a potential oncogenic driver and underscore the importance of recognizing this fusion-defined tumor as a distinct variant within the astroblastoma-like spectrum.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Case report of a rare TCF3::BEND2-fused primary intracranial neuroepithelial neoplasm in a female child

  • 期刊论文

  • 发表日期：

    2026年5月13日

查看全文
  • Qiang Liu,
  • Xiaochuan Dong,
  • Kang Qian,
  • Baoping Zheng,
  • Zhendong Li,
  • Youfan Ye,
  • Haijun Wang

摘要

Astroblastoma, MN1-altered, is a rare circumscribed glial neoplasm defined by alterations in the MN1 gene and often the MN1::BEND2 fusion. However, it is noted that a subset of these tumors lacks the classic astroblastic perivascular pseudorosettes, which can complicate diagnosis. We report a diagnostically challenging case in a 6-year-old female presenting with gait disturbance and limb weakness. MRI identified a well-defined fourth ventricular roof mass causing obstructive hydrocephalus. Histology post-resection revealed a solid tumor composed of epithelioid cells arranged in sheets and nests, exhibiting abundant cytoplasm, nuclear atypia, and prominent grooves, but no astroblastic pseudorosettes or significant mitosis. Immunohistochemically, tumor cells were negative for GFAP and Olig2, showed only focal EMA expression, but exhibited diffuse PR positivity. Methylation profiling did not match any established WHO CNS5 subtype, while targeted NGS identified a defining TCF3::BEND2 in-frame fusion. This case supports the existence of a phenotypically distinct variant within the spectrum of BEND2-rearranged neuroepithelial tumors, characterized by the TCF3::BEND2 fusion. Although molecularly related to MN1-altered astroblastoma, it displays distinct histological and immunophenotypic features. These findings further support the role of BEND2 as a potential oncogenic driver and underscore the importance of recognizing this fusion-defined tumor as a distinct variant within the astroblastoma-like spectrum.