Divito Anthony, Keller Jeffrey T, Hagen Matthew, Zuccarello Mario
Department of Neurosurgery, University of Cincinnati (UC) College of Medicine, Cincinnati, OH, USA.
Department of Neurosurgery, University of Cincinnati (UC) College of Medicine, Cincinnati, OH, USA ; Comprehensive Stroke Center at UC Neuroscience Institute, OH, USA ; Mayfield Clinic, Cincinnati, OH, USA.
Surg Neurol Int. 2014 Nov 12;5:158. doi: 10.4103/2152-7806.144595. eCollection 2014.
The cerebellopontine angle (CPA) is a common location for primary tumors, most often vestibular schwannomas, and also meningiomas, dermoids, and a host of other neoplasms. Our case report illustrates how radiologic and histopathologic presentations of an unusual variant of ependymal neoplasm can be diagnostically challenging and how accurate diagnosis can affect treatment protocols.
Our patient had a CPA mass that was a variant of ependymoma known as tanycytic ependymoma that mimicked vestibular schwannoma radiologically and during intraoperative pathologic examination. Diagnosis as a World Health Organization (WHO) grade II tanycytic ependymoma was supported by its appearance on evaluation of the permanent sections, its diffuse immunoreactivity for glial fibrillary acidic protein (GFAP), and the perinuclear dot-and-ring-like staining for epithelial membrane antigen (EMA).
Our patient's CPA mass initially believed to be a vestibular schwannoma on preoperative evaluation, surgical appearance, and intraoperative pathologic consultation was then correctly diagnosed as a WHO grade II tanycytic ependymoma on permanent histologic sections with the assistance of immunohistochemical stains, including EMA. After this definitive diagnosis, our patient's adjuvant treatment was adjusted. Earlier diagnosis could have provided guidance for goals of resection and prompt initiation of adjuvant treatment.
桥小脑角（CPA）是原发性肿瘤的常见部位，最常见的是前庭神经鞘瘤，也有脑膜瘤、皮样囊肿及许多其他肿瘤。我们的病例报告说明了室管膜瘤一种不寻常变体的放射学和组织病理学表现如何在诊断上具有挑战性，以及准确诊断如何影响治疗方案。
我们的患者有一个CPA肿块，是室管膜瘤的一种变体，称为伸长细胞型室管膜瘤，在放射学检查和术中病理检查时类似于前庭神经鞘瘤。在对永久切片的评估中其表现、对胶质纤维酸性蛋白（GFAP）的弥漫性免疫反应以及对上皮膜抗原（EMA）的核周点状和环状染色支持将其诊断为世界卫生组织（WHO）二级伸长细胞型室管膜瘤。
我们患者的CPA肿块在术前评估、手术外观和术中病理会诊时最初被认为是前庭神经鞘瘤，随后在包括EMA在内的免疫组织化学染色的帮助下，在永久组织切片上被正确诊断为WHO二级伸长细胞型室管膜瘤。在明确诊断后，我们患者的辅助治疗得到了调整。更早的诊断本可为切除目标和辅助治疗的及时启动提供指导。
