[Benefits and Pitfalls of Re-Operation for Recurrent Meningioma].

Malignant forms of meningioma, such as atypical and anaplastic meningiomas, commonly relapse. Recently, there have been many reports elucidating the molecular biological mechanisms underlying meningioma recurrence. Tumors with loss of CDKN(cyclin dependent kinase)2A and 2B or lack of the tri-methylation of lysine 27 on histone H3 protein have a particularly high recurrence rate. In general, primary treatment for recurrent meningiomas comprises stereotactic radiosurgery(SRS)or stereotactic radiotherapy(SRT). However, re-operation is recommended for SRS-, SRT-refractory tumors. One of the benefits of reoperation is that it allows tumor control while decompressing the normal tissue, and changing the tumor microenvironment. Another is that it facilitates the acquisition of pathological and molecular genetic information, which can enable clinicians to recommend precision medicine. However, during reoperation, it is often difficult to detach the tumor from the surrounding brain tissue and cranial nerves because of severe adhesion. In cases of malignant meningiomas with multiple relapses, it is important to share the purpose and goal of the surgery with the patients and their families. In other words, which is being prioritized more, a high resection rate or functional outcomes? Furthermore, salvage surgery should also be a consideration.