ABSTRACT
Objective To investigate the imaging and pathological features of intracerebral demyelination pseudotumor(DPT)so as to provide references for clinical diagnosis and treatment.Methods The medical records of 18 intrathecal DPT patients confirmed pathologically in some hospital from May 2010 to March 2021 were analyzed retrospectively,involving in the findings of imaging(MRI and CT),cerebrospinal fluid immunologic examination and histopathologic examination.Results All the patients had the lesions located in the supratentorial brain parenchyma,including 15 ones with single lesions and 3 ones with multiple lesions.In CT images,the lesions had slightly hypodense changes in 13 cases and isodense changes in 5 cases.In MRI images,the lesions showed homogeneous long T1 and long T2 signals in 9 cases,inhomogeneous long T1 and long T2 signals in 7 cases,mixed signals in 2 cases,accompanying cystic degeneration and necrosis in 3 cases,mild edema around the lesions in 10 cases and severe edema in 8 cases;enhanced scans found open ring-like enhancement in 10 cases,nodular enhancement in 6 cases,multiple openings in 2 cases and the long axis of the lesion perpendicular to the lateral ventricle in 8 cases.Immunologic examination of cerebrospinal fluid detected increased content of myelin alkaline protein and positive changes of immunoglobulin G(IgG)at the oligoclonal band.Histopathological examination found a large number of scattered or clustered macrophages in the lesion area and circular lymphocyte infiltration around the blood vessels.Conclusion Intracerebral DPT has the imaging features of open ring-like enhancement and distribution perpendicular to the lateral ventricles and the histopathologic features of macrophage and lymphocyte infiltration.
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.