De novo dedifferentiated SDH-deficient gastrointestinal stromal tumor with MDM2 amplification: case report and literature review

Frontiers in Oncology

Oncology

Wei-Ming Zhang¹  Zhi-Hong Zhang¹  Qi-Xing Gong¹  Ying Ding¹  Jia-Wen Zhang¹ 

[1]Department of Pathology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China

关键词: gastrointestinal stromal tumor;    dedifferentiation;    SDH;    MDM2;    p53;   

DOI  :  10.3389/fonc.2023.1233561

 received in 2023-06-02, accepted in 2023-08-17,  发布年份 2023

来源: Frontiers

【 摘 要 】

The dedifferentiation of the gastrointestinal stromal tumors (GISTs) has been reported in a small number of cases, usually under the pressure of the tyrosine kinase inhibitor (TKI) treatment. Herein, we described a de novo dedifferentiated GIST with the SDH deficiency in a 32-year-old Chinese woman. The tumor was located on the lesser curvature of the gastric antrum, measuring 4.1x9.1 cm2. Microscopically, the tumor was composed of 2 distinct morphological populations, mild epithelioid cells arranged in the multinodular growth pattern and hyperchromatic spindle cells arranged in the fascicular or sheet-like architecture. The two zones showed different immunophenotypes. The former proved to be an epithelioid GIST with the positive expression for C-KIT, DOG-1, and CD34, and the latter expressed the CKpan and P53, but negative for the C-KIT, DOG-1, and CD34. However, the SDHB staining was negative in both areas. Genetically, the next-generation sequencing (NGS) analysis showed the SDHC mutation (p.S48*) in both components and the MDM2 amplification was only in the spindle cell area. The lesion was diagnosed as the SDH-deficient GIST with the epithelial cell dedifferentiation. We proposed that the P53 associated gene alteration or other alternative escape mechanisms for the KIT-independent signaling pathways might play a role in the dedifferentiation.

【 授权许可】

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Copyright © 2023 Gong, Ding, Zhang, Zhang and Zhang