Low-Grade Glioma with Foci of Early Transformation Does Not Necessarily Require Adjuvant Therapy After Radical Surgical Resection.

Background: Low-grade glioma (LGG) is a slow-growing tumor often found in young adults with minimal or no symptoms. As opposed to true low-grade lesions such as dysembryoplastic neuroepithelial tumors, they are associated with continuous growth and inevitable malignant transformation.

Methods: Case series of patients who have had en bloc resection of LGG with foci of anaplasia found embedded within the tumor specimen and not at margins. Patients were offered and agreed to a conservative approach avoiding adjuvant therapy.

Results: In the current case series, we describe a small subset of LGG that have shown foci of high-grade glioma but have shown behavior and growth tendencies similar to LGG after radical surgical resection. No patient to date has shown recurrent disease requiring adjuvant therapy.

Conclusions: This case series supports the use of early aggressive surgical treatment of grade II gliomas that are premalignant. It acts as proof of concept that after radical resection, the presence of small foci of transformation embedded within grade II tumor may be treated with close radiologic surveillance rather than immediate adjuvant therapy.