Ependymoma of the cauda equina

Area of Science:

• Neuro-oncology
• Pathology
• Thoracic Medicine

Background:

• Myxopapillary ependymomas (MPEs) are typically benign spinal tumors.
• While MPEs can metastasize via cerebrospinal fluid (CSF) pathways, extraneural spread is exceptionally rare.
• Pleural metastasis from a spinal ependymoma is an exceedingly uncommon presentation.

Observation:

• A 67-year-old woman presented with dyspnea following recurrent cauda equina MPEs.
• Chest X-ray revealed multiple pleural lesions.
• These lesions were diagnosed as MPE metastases.

Findings:

• The MIB-1 proliferation index showed an increase from the initial tumor (3.1%) through recurrences (14.2%, 11.2%) to the pleural metastasis (12.0%).
• This suggests a potential for increased proliferative activity correlating with metastatic potential.

Implications:

• This case underscores the importance of considering extraneural metastasis in patients with a history of spinal ependymomas, even with initially benign histology.
• The findings may prompt further investigation into the biological mechanisms driving MPE metastasis.
• Increased vigilance and diagnostic consideration for rare metastatic sites like the pleura are warranted.