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Cytokeratin positivity in myxopapillary ependymoma--a potential diagnostic pitfall
Sundus A Hussein1, Monalisa Sur
1Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada. sunoflife2000@hotmail.com
Background:
Myxopapillary ependymomas (MPE) occur in the filum terminale of the spinal cord, but also present in extra-spinal locations such as subcutaneous tissue and brain. They are slow growing grade I gliomas. Areas of solid growth pattern with aggregates of cells with "epithelioid morphology" seen in MPE can mimic metastatic carcinoma. The presence of occasional cells with clear cytoplasm and morphology can resemble Chordoma. Diagnosis can be missed due to these morphological similarities, which could affect patient management and hence, long term survival.
Case Presentation:
We describe two cases of MPE with cytokeratin (AE1 AE3, CAM 5.2, Cytokeratin 7 and cytokeratin 20) expression.
Conclusion:
MPE can be positive for Cytokeratins (CAM 5.2, AE1 AE3, CK7) and focally for EMA, which could be misdiagnosed as metastatic carcinoma. In cases demonstrating epithelioid and clear cell morphology, the diagnosis of MPE should be made in conjunction with histology, proper immunohistochemical profile which includes co-expression of GFAP, S-100 protein and epithelial markers, radiologic findings and site. It is important to be aware of the cytokeratin profile in MPE to avoid erroneous diagnosis with other tumour entities.
Insights
Myxopapillary ependymomas (MPE) can express cytokeratins, mimicking metastatic carcinoma. Accurate diagnosis requires considering histology, immunohistochemistry, and imaging to ensure proper patient management and improve survival.
Area of Science:
- Neuro-oncology
- Surgical Pathology
Background:
- Myxopapillary ependymomas (MPE) are slow-growing Grade I gliomas typically found in the filum terminale.
- MPE can occur in extra-spinal locations, including subcutaneous tissue and brain.
- Epithelioid morphology in MPE can resemble metastatic carcinoma, and clear cell morphology can mimic Chordoma, potentially leading to diagnostic challenges.
Purpose of the Study:
- To report two cases of Myxopapillary Ependymoma (MPE) with cytokeratin expression.
- To highlight the potential for misdiagnosis of MPE due to overlapping morphological and immunohistochemical features with other tumors.
Main Methods:
- Case presentation of two MPE patients.
- Immunohistochemical analysis including cytokeratins (AE1 AE3, CAM 5.2, Cytokeratin 7, Cytokeratin 20) and EMA.
Main Results:
- Myxopapillary ependymomas (MPE) demonstrated positivity for cytokeratins (CAM 5.2, AE1 AE3, CK7) and focal EMA expression.
- These findings underscore the potential for MPE to be misdiagnosed as metastatic carcinoma.
Conclusions:
- MPE can exhibit cytokeratin and EMA positivity, leading to potential misdiagnosis as metastatic carcinoma.
- Diagnosis of MPE with epithelioid or clear cell morphology requires integration of histology, immunohistochemistry (GFAP, S-100, epithelial markers), and imaging.
- Awareness of the cytokeratin profile in MPE is crucial to avoid erroneous diagnoses and ensure appropriate patient management.