Immature teratomas of the central nervous system: is adjuvant therapy mandatory?

Immature teratomas of the central nervous system (CNS) are rare neoplasms. Although adjuvant therapy is generally recommended after resection, the exact role of each therapeutic modality is not yet established. The purpose of this study was to analyze the clinicopathological correlation and the role of resection to define the optimal treatment modalities for immature teratomas of the CNS.

Between 1987 and 2002, eight patients underwent radical surgery for a lesion diagnosed as a CNS immature teratoma at the authors' institution. The clinical courses of these patients and the pathological features of their tumors were retrospectively reviewed. Gross-total resection (GTR) was achieved in six patients at the initial operation. The mean follow-up period was 75 months. Two patients received postoperative adjuvant therapies and two patients did not, against medical advice. None of the four patients experienced recurrence after long-term follow up. Another four patients, all of whom underwent GTR of the tumor, did not receive adjuvant therapy as part of a prospective treatment scheme. One of them exhibited early recurrence and metastasis. The tumor had pathological features denoting a high-grade (Norris Grade III) lesion and neurocytomatous differentiation.

Aggressive resection seems to be of utmost importance in the treatment of immature teratomas of the CNS. Adjuvant chemotherapy and radiotherapy can be deferred if GTR is achieved in low-grade, immature teratomas, but adjuvant therapies may be warranted for high-grade ones.