Supratentorial Extraventricular Ependymomas: Imaging Features and the Added Value of Apparent Diffusion Coefficient

Area of Science:

• Neuro-oncology
• Radiology
• Pathology

Background:

• Ependymal tumors are primary central nervous system neoplasms.
• Distinguishing between intraventricular and extraventricular ependymomas is crucial for prognosis.

Purpose of the Study:

• To enhance the understanding and diagnosis of intracranial ependymal tumors.
• To compare the clinical, radiological, and prognostic features of supratentorial extraventricular and intraventricular ependymomas.

Main Methods:

• Retrospective analysis of 48 supratentorial extraventricular ependymomas and 74 intraventricular ependymomas.
• Comparison of clinical, radiological (including apparent diffusion coefficient - ADC values), and survival data.

Main Results:

• Supratentorial extraventricular ependymomas (often frontal, grade III) exhibited larger cysts, significant enhancement, low ADC values, and higher mortality (41.3%).
• Intraventricular ependymomas (often fourth ventricle, grade II) showed smaller cysts, moderate enhancement, high ADC values, and lower mortality (20.7%).
• Young age, high grade, and low ADC values were poor prognostic indicators for extraventricular tumors only.

Conclusions:

• Radiological features, clinical data, and diffusion-weighted imaging (DWI) improve diagnosis and prognosis of intracranial ependymal tumors.
• Quantitative information from DWI aids in understanding tumor pathophysiology.