A case of glioblastoma resected immediately after administering bevacizumab: consideration on histopathological findings and safety of surgery.

Surgery after administering bevacizumab should be carefully considered particularly because of wound healing concerns. A 27-year-old man presented with multiple tumor recurrences after gross total removal of a left temporal oligodendroglioma (1p/19q-noncodeleted). Whole brain radiotherapy with concomitant temozolomide and bevacizumab was immediately prescribed; however, the patient's condition deteriorated because of brain herniation. Three days after administering bevacizumab, an emergency tumor removal with external decompression and a ventriculo-peritoneal shunt was performed. The surgery and postoperative clinical course were uneventful. On histopathological examination, the tumor showed findings such as tumor vessel thrombosis, numerous interstitial red blood cells, and cells with degraded, fragmented nuclei possibly suggesting apoptosis, which could be attributable to bevacizumab. Performing craniotomy shortly after administering bevacizumab is not recommended; however, it can still be safely performed as long as surgery and wound management is carefully performed. Vessel thrombosis might be among the mechanisms of action of bevacizumab.