Tabrizi Roshanak Daneshzadeh, Mittelbronn Michel, Marquardt Gerhard, Hattingen Elke
Institute of Neuroradiology, Department of Neurosurgery, Goethe University Hospital Frankfurt, Goethe University Frankfurt, Frankfurt am Main, Germany.
Childs Nerv Syst. 2012 Oct;28(10):1791-4. doi: 10.1007/s00381-012-1839-0. Epub 2012 Jun 21.
Pilocytic astrocytoma (PCA) is the most common CNS tumor in primary school-aged children. Herein, we report the case of a 7-month-old female child with a large cerebellar hypodense tumor on computer tomography occupying nearly the whole cerebellar hemisphere. Magnetic resonance imaging revealed characteristic features of a PCA, depicting a mass with hyperintense solid and cystic areas on T2-weighted images and with marked solid and ring-like enhancement pattern. Histopathological and immunohistochemical analysis showed partially typical features of a PCA, but also atypical features such as a high proliferation rate, hypercellularity, and focally diffuse infiltration pattern were present. However, definite signs of transformation to an anaplastic PCA were not observed. We therefore classified the tumor as pilocytic astrocytoma with signs of atypia instead of simple WHO grade I pilocytic astrocytoma. The case illustrates that neuroimaging features may give very important clues for the definite diagnosis in histopathologically atypical PCA.
毛细胞型星形细胞瘤（PCA）是小学学龄儿童中最常见的中枢神经系统肿瘤。在此，我们报告一例7个月大的女童病例，其计算机断层扫描显示小脑有一个大的低密度肿瘤，几乎占据整个小脑半球。磁共振成像显示出PCA的特征性表现，在T2加权图像上呈现出高信号的实性和囊性区域的肿块，并伴有明显的实性和环状强化模式。组织病理学和免疫组织化学分析显示出PCA的部分典型特征，但也存在非典型特征，如高增殖率、细胞增多以及局灶性弥漫浸润模式。然而，未观察到向间变性PCA转变的确切迹象。因此，我们将该肿瘤分类为具有非典型特征的毛细胞型星形细胞瘤，而非单纯的世界卫生组织I级毛细胞型星形细胞瘤。该病例表明，在组织病理学非典型的PCA中，神经影像学特征可能为明确诊断提供非常重要的线索。
