Magnetic resonance imaging features of medulloblastoma in adults and children

Abstract

Objective To analyze the MRI features findings of adults and children with medulloblastoma for the improvement of the understanding of medulloblastoma. Methods Retrospective analysis of 36 patients with medulloblastoma confirmed by pathology in Guangdong Nongken Central Hospital was conducted, and these patients were divided into two groups: 25 patients in the children group and 11 patients in the adult group, followed by undergoing plain and contrast-enhanced MRI. Then the MRI features including the tumor location, the maximum diameter of the tumor, the boundary, cystic changes, parenchymal region enhancement, peritumoral edema, obstructive hydrocephalus, and ependymal-implantation migration were observed and compared. Results The medulloblastoma in all patients located in infratentorial area, and the tumors in children were commonly found in vermis (21/25), while adult lesions were mostly presented in the cerebellar hemisphere (9/11), with significant differences (P=0.000). In the adult group, cystic changes (11/11) and peripheral edema (7/11) were higher than those in the children group (16/25) and edema (4/25). The differences in the tumor cystic lesions and peritumoral edema were statistically significant in the both groups (P=0.034, P=0.008). The maximum diameter of children patients' tumors was (4.50±0.58) cm, and the maximum data was more than 4 cm in 17 patients; the maximum diameter of adults patients' tumors was (5.24±1.36) cm, and it was more than 4 cm in 8 patients, with statistical significance (Z=-0.895, P>0.05). There was no significant difference in boundary, obstructive hydrocephalus, and ependymal-implantation migration between the two groups (all P values>0.05). The MRI of parenchymal region in all patients with medulloblastoma showed a slightly higher signal on T2WI and T2-FLAIR, and a low signal on T1WI. And 12 patients underwent diffusion-weighted imaging examination (5 children and 7 adults), and the parenchymal region of the tumor showed diffuse limitation. After the enhanced scanning, the parenchymal region of the tumor in both groups showed mild to moderate enhancement. Conclusions The medulloblastoma of children often occurs in the cerebellar vermis, while the tumor in adults commonly locates in the cerebellar hemisphere. The tumor cystic changes and peritumoral edema in children are less frequent than those in adults. The medulloblastoma both in children and adults commonly manifests a well-defined mass with mild to moderate enhancement, and is prone to cause obstructive hydrocephalus and probably has the ependymal implantation metastasis. Key words: Medulloblastoma; Brain neoplasms; Magnetic resonance imaging; Imaging features; Adult; Child