[Pyoktanin blue injection for resection of cystic brain tumor: a case report].

Pyoktanin blue is an agent that is often used during STA-MCA anastomosis. In this report, we inject it into a cystic tumor for complete resection, and we report its usefulness. The patient was a 57-year-old female. She suffered from progressive cerebellar ataxia. CT and MR showed a cystic metastatic tumor at the right cerebellar hemisphere, 40mm in diameter. Craniotomy was performed, 5cm in diameter, using the right suboccipital approach. After peeling off the tumor from the surface layer of the brain, we injected diluted pyoktanin blue into the tumor to dye the inside wall. After that, the tumor was peeled off completely without exposing the dyed inside wall. We sometimes find it difficult to distinguish tumor from brain if there is tearing of the tumor wall. Tearing of the tumor can be prevented by injecting pyoktanin blue into it, and making the inside wall visible. Using this procedure, we think a tumor can be resected without residual tumor or damage to the brain. Although we have used this method only a few times, we think it is an easy and useful technique to inject pyoktanin blue into a cystic tumor during its resection.