Imaging and pathological features of pilomyxoid astrocytoma in children / 中国实用儿科杂志

ABSTRACT

OBJECTIVE: To investigate the imaging characteristics and their relationship with histopathological changes of pilomyxoid astrocytomas(PMA)in children. METHODS: The CT and MRI findings as well as clinical data of 20 pediatric patients with PMA admitted to Beijing Tiantan Hospital,Capital Medical University between October 2010 and June 2018 were analyzed retrospectively,and their clinical features,pathological and immunohistochemical results were also analyzed.RESULTS: There were 15 males and 5 females in total 20 patients with PMA. Tumors were located at cerebellar hemisphere in 10,cerebral hemisphere in 5,chiasmatic-hypothalamic region in 4 and at the third ventricle in 1. Of 20 patients with PMA,10 presented hypodense on CT images,11 showed mixed signal intensity on both T1 and T2 weighted images on MRI,7 demonstrated hypointensity on T1 WI and 7 had hyperintensity on T2 WI. Absence of diffusion restriction were noticed in 12 tumors. The tumors showed significant inhomogeneous enhancement in 17 cases under MRI enhanced screening. The cases of neoplasm clear margin,necrosis inside tumors and peritumor edema were 18,16 and 11,respectively. Histopathologically,PMA was characterized by the presence of bipolar spindle cells,angiocentric arrangement,prominent myxoid background and the lack of Rosenthal fibers. CONCLUSION: The pediatric PMA has low-grade tumor features and characteristic imaging features. There are several imaging features which are relatively specific for PMAon CT and MRimages,such as heterogeneous texture,clear border,cystic changes of edge and inhomogeneous enhancement. CT and MRI may provide valuable information for preoperative diagnosis,clinical treatment and prognostic evaluation in patients with PMA.