Intraparenchymal subependymoma: Case report and literature review

Abstract

Background: Intracranial subependymomas are rare slow-growing benign tumors typically located in the ventricular system, accounting for 0.07–0.7% of all intracranial neoplasms. Intraparenchymal subependymoma is extremely rare lesions, imposing a challenging diagnosis and management. Case Description: We describe a case of a supratentorial intraparenchymal mass on left occipital lobe in a 26-year-old woman with progressive headache and visual impairment. Differential diagnosis mainly included gliomas, neuronal-glial tumors, ependymoma, and subependymoma. Complete surgical resection was performed and histopathology analysis confirmed diagnosis of subependymoma. Despite its benign behavior the Ki67/MIB-1 labeling index assessed by immunohistochemistry was 5%. After 1 year of follow-up she was free of tumor recurrence. Conclusion: Intraparenchymal subependymoma is extremely rare tumors and literature review showed only 11 cases reported. In general, they are misdiagnosed as other tumors, so careful attention on clinical and radiological features must be taken when looking at a tumor close to the ventricular system, even though it does not have any obvious direct connection to it. Despite its benign nature, total removal must be attempted given that there are reports of recurrence, especially in partially removed tumors with high proliferation index. The role of adjuvant therapy is still limited and new treatment options are being developed as our knowledge on biological and molecular characteristics advances.

A Case of Cerebellar Intraparenchymal Subependymoma with Next-Generation Sequencing Analysis

“…The previously reported 19 cases of intraparenchymal or cerebellopontine angle subependymoma, including the present case, are listed in Table 1. 10 In all cases, the most frequently affected site was the parietal lobe or cerebellopontine angle, and the common clinical manifestations were seizure and headache. The mean ages of patients with intraparenchymal or cerebellopontine angle subependymoma were lower than those with ventricular subependymomas (28.6 and 50.0 years, respectively).…”

“…Rare cases of subependymomas have been reported in the cerebral parenchyma (frontal or parietal lobe or thalamus), midbrain, cerebellopontine angle, and the extramedullary region of the spinal cord. [1][2][3][4][5][6][7][8][9][10][11][12][13] These tumors are often found incidentally during neuroimaging or autopsy, and some patients may show symptoms associated with ventricular obstruction or increased intracranial pressure. 12,14 They can occur in all age groups, but a higher incidence is observed in middle to older aged individuals.…”