Department of Pathology, University of Iowa Hospitals and Clinics, Iowa City, IA 52242, United States.
Department of Radiology, University of Iowa Hospitals and Clinics, Iowa City, IA 52242, United States.
Pathol Res Pract. 2023 Dec;252:154922. doi: 10.1016/j.prp.2023.154922. Epub 2023 Nov 8.
Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) is a recently described entity. The clinicopathological features and prognosis of the molecular subgroups of these rare tumors is poorly understood. In this study, we presented a small case series of three new cases and integrated the data with published cases in the literature to characterize the similarities and differences of molecular subgroups of PLNTY.
We searched our institutional archive for PLNTY cases and searched PubMed and Web of Science for relevant data. Demographic, clinical, radiologic, histopathological, molecular, and follow-up data of our four cases with published cases were integrated for final analyses.
We identified three institutional cases of PLNTY. The median age of our patients was 17 years (range: 13-42). All patients had a prior history of chronic seizures and all had tumors affecting the temporal lobes. Histopathologically, all cases showed oligodendroglial-like morphology with intratumoral calcifications and at least partially infiltrative growth patterns. Tumor cells were immunoreactive with CD34 and GFAP. Genetically, all cases harbored BRAF V600E mutations. Integrated analyses, including a total of 67 cases, demonstrated that PLNTYs with FGFR2 mutation were significantly younger (median age 11.0 years) than those with BRAF V600E or FGFR3 fusions (median age 41.0 and 16.0 years, respectively). All BRAF V600E-positive PLNTYs were free of tumor recurrence, while four of PLNTYs in other molecular subgroups developed tumor recurrence by imaging.
Our study suggests that PLNTYs have distinct clinicopathological features and are driven by genetic alterations in the MAPK pathway. The molecular subgroups of PLNTYs share similar findings, but also demonstrate distinct patient demographics.
年轻多形性低级别神经上皮肿瘤（PLNTY）是一种最近描述的实体。这些罕见肿瘤的分子亚群的临床病理特征和预后尚不清楚。在本研究中，我们报告了三例新病例的小病例系列，并整合了文献中的发表病例数据，以描述 PLNTY 分子亚群的相似和不同之处。
我们在机构档案中搜索 PLNTY 病例，并在 PubMed 和 Web of Science 上搜索相关数据。我们整合了我们的四个病例的人口统计学、临床、放射学、组织病理学、分子和随访数据以及发表的病例数据进行最终分析。
我们确定了三个机构的 PLNTY 病例。我们的患者中位年龄为 17 岁（范围：13-42 岁）。所有患者均有慢性癫痫发作史，且所有患者的肿瘤均影响颞叶。组织病理学上，所有病例均显示少突胶质样形态，伴有肿瘤内钙化和至少部分浸润性生长模式。肿瘤细胞对 CD34 和 GFAP 呈免疫反应性。遗传上，所有病例均携带 BRAF V600E 突变。综合分析，包括 67 例病例，表明 FGFR2 突变的 PLNTY 明显更年轻（中位年龄 11.0 岁），而 BRAF V600E 或 FGFR3 融合的 PLNTY 分别为 41.0 岁和 16.0 岁。所有 BRAF V600E 阳性的 PLNTY 均无肿瘤复发，而其他分子亚群的 4 例 PLNTY 则通过影像学显示肿瘤复发。
我们的研究表明，PLNTY 具有明显的临床病理特征，并受 MAPK 通路中遗传改变的驱动。PLNTY 的分子亚群具有相似的发现，但也表现出不同的患者特征。
