Department of Pathology and Laboratory Medicine, University of Miami Miller School of Medicine, Miami, FL.
Adv Anat Pathol. 2024 Nov 1;31(6):354-363. doi: 10.1097/PAP.0000000000000463. Epub 2024 Sep 4.
The diagnosis of gastrointestinal stromal tumors (GISTs) is generally straightforward using a combination of histologic evaluation and pertinent immunohistochemical staining with CD117/kit and DOG-1 (discovered on GIST) antibodies. However, this tumor can be challenging in cases with an unusual morphology, in limited biopsies, for those in uncommon sites, post-treatment, and when other neoplasms express CD117/kit and DOG-1, thereby mimicking GIST. Finding epithelioid GISTs in the stomach in younger patients should prompt testing for succinate dehydrogenase (SHD)-deficiency using immunohistochemical staining for subunit B (SDHB). However, SDH-deficient GISTs can also arise in older patients, or as part of the Carney triad or Carney-Stratakis syndrome. GISTs with PDGFRA mutations can also prove difficult if they lack kit expression. It is also important to consider morphologic and immunophenotypic changes associated with treatment, including the potential absence of kit expression, particularly in GISTs that have metastasized. Therefore, obtaining clinical information regarding prior therapy with a tyrosine kinase inhibitor (TKI) is crucial.
胃肠道间质瘤（GISTs）的诊断通常很简单，结合组织学评估和特定的免疫组织化学染色，使用 CD117/kit 和 DOG-1（GIST 发现）抗体。然而，在形态不寻常、活检有限、发生部位不常见、治疗后以及其他肿瘤表达 CD117/kit 和 DOG-1 从而模拟 GIST 的情况下，这种肿瘤可能具有挑战性。在年轻患者的胃中发现上皮样 GIST 时，应使用免疫组织化学染色检测琥珀酸脱氢酶（SDH）亚基 B（SDHB）以进行 SHD 缺陷检测。然而，SDH 缺陷型 GIST 也可发生于老年患者，或作为 Carney 三联征或 Carney-Stratakis 综合征的一部分。如果缺乏 kit 表达，具有 PDGFRA 突变的 GIST 也可能难以诊断。还需要考虑与治疗相关的形态学和免疫表型变化，包括 kit 表达的潜在缺失，尤其是在已经转移的 GIST 中。因此，获得有关先前使用酪氨酸激酶抑制剂（TKI）治疗的临床信息至关重要。
