Departments of Pathology.
Hematology & Oncology.
Am J Surg Pathol. 2022 Sep 1;46(9):1309-1313. doi: 10.1097/PAS.0000000000001887. Epub 2022 Mar 15.
The PLEKHH2::ALK fusion is a rarely reported gene fusion identified predominantly in lung adenocarcinomas. Tumors with this fusion have been reported to be of durable response to ALK inhibitors. We herein present the case of a 21-year-old woman with a histomorphologically heterogenous mesenchymal neoplasm of the pelvis, expressing both s100 and CD34, with subsequently identified PLEKHH2::ALK fusion. To our knowledge, only a single mesenchymal neoplasm with this gene fusion has been previously reported. We propose that this tumor represents one with a novel ALK fusion in the emerging family of s100 and CD34 expressing mesenchymal neoplasms with oncogenic kinase alterations akin to NTRK -rearranged mesenchymal neoplasms, rather than inflammatory myofibroblastic tumor. Importantly, this tumor demonstrated a significant response to the ALK inhibitor brigatinib.
PLEKHH2::ALK 融合是一种罕见报道的基因融合，主要在肺腺癌中发现。具有这种融合的肿瘤对 ALK 抑制剂有持久的反应。我们在此报告了一例 21 岁女性的骨盆间叶性混杂性肿瘤，表达 s100 和 CD34，随后发现 PLEKHH2::ALK 融合。据我们所知，之前仅报道过一例具有这种基因融合的间叶性肿瘤。我们提出，该肿瘤代表一类具有新型 ALK 融合的肿瘤，这些肿瘤属于 s100 和 CD34 表达的间叶性肿瘤，具有致癌激酶改变，类似于 NTRK 重排的间叶性肿瘤，而不是炎症性肌纤维母细胞瘤。重要的是，该肿瘤对 ALK 抑制剂布加替尼（brigatinib）有明显的反应。
