From the Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York, USA.
Department of Pathology and Laboratory Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA.
J Neuropathol Exp Neurol. 2021 Oct 26;80(10):933-943. doi: 10.1093/jnen/nlab089.
Resected lesions from the pineal region are rare specimens encountered by surgical pathologists, and their heterogeneity can pose significant diagnostic challenges. Here, we reviewed 221 pineal region lesions resected at New York-Presbyterian Hospital/Columbia University Irving Medical Center from 1994 to 2019 and found the most common entities to be pineal parenchymal tumors (25.3%), glial neoplasms (18.6%), and germ cell tumors (17.6%) in this predominantly adult cohort of patients. Six cases of a rare midline entity usually found exclusively in the fourth ventricle, the rosette-forming glioneuronal tumor, were identified. These tumors exhibit biphasic morphology, with a component resembling pilocytic astrocytoma admixed with variable numbers of small cells forming compact rosettes and perivascular pseudorosettes. Targeted sequencing revealed a 100% co-occurrence of novel and previously described genetic alterations in the mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) signaling pathways, suggesting a synergistic role in tumor formation. The most common recurrent mutation, PIK3CA H1047R, was identified in tumor cells forming rosettes and perivascular pseudorosettes. A review of the literature revealed 16 additional cases of rosette-forming glioneuronal tumors in the pineal region. Although rare, this distinctive low-grade tumor warrants consideration in the differential diagnosis of pineal region lesions.
切除的松果体区域病变标本是外科病理学家罕见遇到的标本，其异质性可能会带来重大的诊断挑战。在这里，我们回顾了 1994 年至 2019 年期间在纽约长老会医院/哥伦比亚大学欧文医学中心切除的 221 例松果体区域病变，在这个以成年患者为主的患者群体中，最常见的实体是松果体实质肿瘤（25.3%）、神经胶质瘤（18.6%）和生殖细胞肿瘤（17.6%）。鉴定了 6 例罕见的中线实体病变，通常仅在第四脑室中发现，即玫瑰花形成的神经胶质神经元肿瘤。这些肿瘤表现出双相形态，一个成分类似于毛细胞型星形细胞瘤，混合有数量不等的形成致密玫瑰花结和血管周围假玫瑰花结的小细胞。靶向测序显示，在有丝分裂原激活蛋白激酶（MAPK）和磷酸肌醇 3-激酶（PI3K）信号通路中，新的和先前描述的遗传改变的 100%共同发生，提示在肿瘤形成中具有协同作用。在形成玫瑰花结和血管周围假玫瑰花结的肿瘤细胞中鉴定出最常见的复发突变 PIK3CA H1047R。文献复习发现了 16 例松果体区域的玫瑰花形成神经胶质神经元肿瘤。尽管罕见，但这种独特的低级别肿瘤在松果体区域病变的鉴别诊断中值得考虑。
