Introduction: The aim of this paper was to systematically review the evidence linking Propionibacterium acnes (P. acnes) with the develop Tanycytic ependymoma (tcE) is a rare variant of ependymoma and management guidelines for patients with this disease are not established.
Evidence acquisition: We performed a systematic search on Pubmed complimented by hand-searching citation lists to identify patients with pathologically confirmed tcE. Signs and symptoms, radiological and specific pathological findings as well as reported treatment modalities and outcomes were recorded and analyzed.
Evidence synthesis: Fifty-one studies involving a total of 77 patients were identified and included in this review. Most cases of tcEs occurred in the spinal cord (50.6%), followed by lesions located in upper intracranial sites (36.4%) and only a few at the cervicomedullary junction (3.9%). Female to male ratio was calculated as about 1:1.5, with a mean age at diagnosis of approximately 36.1±18 years. Complete resection of the tumor without further additional therapy was the treatment of choice in most cases (63.6%), radiotherapy was considered in 10 cases (13.0%). In 18 reported cases of tcE (23.4%), the treatment was not documented. Defined follow-up periods for patients with tcE were only documented in 44 cases (57.1%), the mean follow-up was 22.3 months. 36 cases (46.8%) had no recurrence of tumor after treatment (26 months mean follow-up).
Conclusions: This comprehensive review on tcEs supports surgery as the initial treatment modality of choice. Radiotherapy can be considered when total gross resection cannot be achieved and allows for prolonged progression-free survival. Given the benign nature of this subtype of ependymoma, aggressive treatment such as chemotherapy is usually not indicated.