Alkonyi Bálint, Nowak Johannes, Gnekow Astrid K, Pietsch Torsten, Warmuth-Metz Monika
Department of Neuroradiology, Universitätsklinikum Würzburg, Josef-Schneider-Strasse 11, 97080, Würzburg, Germany,
Neuroradiology. 2015 Jun;57(6):625-38. doi: 10.1007/s00234-015-1498-4. Epub 2015 Feb 10.
Pilomyxoid astrocytoma (PMA) is a rare WHO grade II tumor occurring most often in young children. PMA is associated with worse outcome as compared to the pathologically related pilocytic astrocytoma (PA). The radiological differentiation of PMAs from PAs is challenging. Furthermore, it is not completely clarified whether PMA is associated with a higher rate of cerebrospinal fluid (CSF) dissemination in the youngest pediatric population as compared to PA. The aim of our study was firstly to compare imaging features of these tumors and, secondly, to evaluate the occurrence of CSF dissemination.
The study population included 15 children with PMA and 32 children with PA. The initial MRI and CT scans from the time of the diagnosis were retrospectively analyzed according to standardized criteria and the findings compared between the two tumor types. Furthermore, we also compared the occurrence of imaging evidences of CSF dissemination.
PMAs showed less frequently cystic components (p = 0.03) and never had large tumor cysts. Gadolinium enhancement of PMAs was more frequently homogeneous (p = 0.006). PMAs appeared to show more often intratumoral hemorrhages (p = 0.047). Within the subgroup of children <6 years of age, the PMA histology tended to have a larger effect on the occurrence of CSF dissemination than the age (p = 0.05 vs. 0.12).
Some imaging features like enhancement pattern or presence of cysts or hemorrhage may help differentiating these low-grade gliomas. Our results confirm previous scarce data suggesting a higher rate of CSF dissemination in PMAs, even in the youngest patient population.
毛黏液样星形细胞瘤（PMA）是一种罕见的世界卫生组织二级肿瘤，最常发生于幼儿。与病理相关的毛细胞型星形细胞瘤（PA）相比，PMA的预后较差。PMA与PA在影像学上的鉴别具有挑战性。此外，与PA相比，在最小的儿科人群中，PMA是否与更高的脑脊液（CSF）播散率相关尚不完全清楚。我们研究的目的首先是比较这些肿瘤的影像学特征，其次是评估CSF播散的发生率。
研究人群包括15例PMA患儿和32例PA患儿。根据标准化标准对诊断时的初始MRI和CT扫描进行回顾性分析，并比较两种肿瘤类型的结果。此外，我们还比较了CSF播散的影像学证据的发生率。
PMA较少出现囊性成分（p = 0.03），且从未有过大的肿瘤囊肿。PMA的钆增强更常呈均匀性（p = 0.006）。PMA似乎更常出现瘤内出血（p = 0.047）。在6岁以下儿童亚组中，PMA组织学对CSF播散发生率的影响似乎比年龄更大（p = 0.05对0.12）。
一些影像学特征，如增强模式、囊肿或出血的存在，可能有助于鉴别这些低级别胶质瘤。我们的结果证实了之前稀少的数据，表明即使在最年幼的患者群体中，PMA的CSF播散率也更高。
