Roth Jonathan, Nass Dvora, Ram Zvi
Department of Neurosurgery, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
Neurosurgery. 2006 Jun;58(6):E1210; discussion E1210. doi: 10.1227/01.NEU.0000215987.74391.8E.
Nonpilocytic low-grade glial tumors in adults occur mostly in the supratentorial compartment. However, a few cases of infratentorial low-grade gliomas (LGG) have been described. The occurrence of LGG in the cerebellum in the setting of a previously existing supratentorial glioma is rare.
We present three young patients with a histologically confirmed diagnosis of long-standing supratentorial LGG. All three patients presented years after their initial diagnosis with a second, nonenhancing lesion in the cerebellum, compatible with the radiological appearance of LGG. Two patients subsequently became symptomatic from these lesions and underwent surgical resection of the cerebellar lesions that were found to have similar pathological features to the original supratentorial tumors. This was confirmed by histology (both patients) and genetic markers (one patient).
Magnetic resonance imaging did not demonstrate tumor continuity between the supratentorial and infratentorial lesions in any of the patients. The third patient has shown no cerebellar symptoms to date and is only followed with periodic magnetic resonance imaging.
The anatomic/pathological basis of these rare cases may include a primary, multicentric tumor formation, or a secondary tumor infiltration of the cerebrocerebellar pathways, leading to the formation of the cerebellar tumor.
成人间变型少突胶质细胞瘤多发生于幕上区域。然而，也有少数幕下低级别胶质瘤（LGG）的病例报道。在先前已存在幕上胶质瘤的情况下，小脑发生LGG的情况较为罕见。
我们报告了三名组织学确诊为长期存在的幕上LGG的年轻患者。所有三名患者在初次诊断多年后，小脑出现了第二个无强化病变，其影像学表现符合LGG。两名患者随后因这些病变出现症状，并接受了小脑病变的手术切除，发现其病理特征与原发幕上肿瘤相似。这通过组织学（两名患者）和基因标记（一名患者）得到证实。
磁共振成像未显示任何一名患者的幕上和幕下病变之间存在肿瘤连续性。第三名患者迄今为止未出现小脑症状，仅通过定期磁共振成像进行随访。
这些罕见病例的解剖学/病理学基础可能包括原发性多中心肿瘤形成，或脑-小脑通路的继发性肿瘤浸润，从而导致小脑肿瘤的形成。
