Department of Neurosurgery, Sainte-Anne Hospital, Paris cedex14, France.
Ann Neurol. 2010 Nov;68(5):727-33. doi: 10.1002/ana.22106.
Seizure is the presenting symptom in most of World Health Organization grade II gliomas (GIIGs). Rarely, a GIIG is discovered incidentally on imaging. Little is known about the natural course and prognosis of incidental GIIGs. The aim of the present study is to characterize their natural history and to investigate whether their clinical and radiological behaviors differ from those of symptomatic GIIGs.
The clinical and radiological findings, treatments, and outcomes of 47 histologically-proven incidental GIIGs were compared with those of 1249 symptomatic GIIGs.
Incidental GIIGs differ significantly from symptomatic GIIGs: they have a female predominance (p = 0.05), smaller initial tumor volumes (p < 0.001), lower incidence of contrast enhancement (p = 0.009), and are more likely to undergo gross total surgical removal (p < 0.001). Proliferation rates were similar to that observed among symptomatic GIIGs. Younger age at the time of discovery, frontal lobes, and noneloquent brain regions were associated with incidental GIIGs, as compared to their symptomatic counterparts. When not treated, incidental GIIGs demonstrated radiological growth (median velocity of diametric expansion at 3.5 mm/year), and became symptomatic at a median interval of 48 months after radiological discovery. Overall, incidental discovery was associated with a significant survival benefit (p = 0.04).
Incidental GIIGs are progressive tumors leading to clinical transformation toward symptomatic GIIGs. They may represent an earlier step in the natural history of a glioma than the symptomatic GIIGs.
癫痫是世界卫生组织（WHO）二级胶质瘤（GIIG）的主要表现症状。然而，少数 GIIG 是在影像学检查中偶然发现的。对于偶然发现的 GIIG，其自然病程和预后知之甚少。本研究旨在描述其自然病史，并探讨其临床和影像学表现是否与症状性 GIIG 不同。
将 47 例经组织学证实的偶然 GIIG 的临床和影像学表现、治疗和转归与 1249 例症状性 GIIG 进行比较。
偶然发现的 GIIG 与症状性 GIIG 有显著差异：女性居多（p=0.05），初始肿瘤体积较小（p<0.001），对比增强发生率较低（p=0.009），更倾向于进行大体全切除（p<0.001）。增殖率与症状性 GIIG 相似。与症状性 GIIG 相比，偶然发现的 GIIG 发生于年龄较小、额叶和非语言功能区。未治疗的偶然发现的 GIIG 表现为影像学生长（直径扩张的平均速度为 3.5mm/年），并在影像学发现后中位 48 个月出现症状。总的来说，偶然发现与显著的生存获益相关（p=0.04）。
偶然发现的 GIIG 是进行性肿瘤，导致临床转化为症状性 GIIG。它们可能代表了 GIIG 自然病史的早期阶段，比症状性 GIIG 更早。
