Symptomatic subependymoma: a clinicopathological and flow cytometric study

Area of Science:

• Neurosurgery
• Neuropathology
• Oncology

Background:

• Subependymomas are rare glial tumors typically found in the fourth ventricle.
• Histopathological features can sometimes overlap with ependymomas, posing diagnostic challenges.
• Understanding prognostic factors is crucial for guiding treatment decisions.

Purpose of the Study:

• To review clinical presentation, diagnosis, surgical findings, and long-term outcomes of intracranial subependymomas.
• To correlate histopathological features and deoxyribonucleic acid (DNA) analysis with patient prognosis.
• To evaluate the role of adjuvant radiotherapy in managing subependymomas.

Main Methods:

• Retrospective review of 21 intracranial subependymoma cases.
• Histopathological analysis including assessment of cytological atypia, mitoses, and ependymoma components.
• Deoxyribonucleic acid (DNA) analysis using flow cytometry.
• Evaluation of radiographic characteristics on computerized tomography (CT) and magnetic resonance imaging (MRI).

Main Results:

• Tumors predominantly located in the fourth ventricle (14/21).
• Radiographic features included isodensity with minimal enhancement on CT and specific MRI signal characteristics.
• Despite atypical features in some cases, tumor location and extent of surgical resection were more significant prognostic indicators than histopathology.
• No progression or tumor-related death in non-irradiated patients after gross total resection.
• Irradiated tumors showed radioresponsiveness, particularly with doses ≥5000 cGy.

Conclusions:

• Surgical resection extent and tumor location are key prognostic factors in subependymoma management.
• Routine postoperative irradiation is not advised; it should be reserved for symptomatic residual or recurrent disease.
• Adjuvant radiotherapy may be considered for specific cases, especially those with residual tumors, given observed radioresponsiveness.