Rapid Regrowth Of Intracranial Transitional (mixed) Type Meningioma After Gamma Knife Radiosurgery.Park Sun Moon11Eulji University Hospital, Daejeon, Republic of Korea Keywords: brain tumor, gamma knife, meningioma, recurrent disease, outcome
Transitional (mixed) type meningioma is classified as grade I in the current WHO system. Intracranial transitional (mixed) type have a benign nature with zero behavior code.
We treated a patient with transitional meningioma at shenoid ridge by GK radiosurgery followed after craniotomy. The residual tumor grew rapidly during 4 months after GK radiosurgery. The postradiosurgical course was uneventful.
The patient was a 56-year-old woman.
She underwent craniotomy for sphenoid ridge meningioma on August 7, 1997 and gamma knife (GK) radiosurgery for the residual or recurrent tumor with an irradiation dose of 15Gy marginal dose(50%) at SNUH on August 14, 2006. The patient admitted to our hospital with complaints of headache, eyeball pain on March 18, 2008. MR imaging demonstrated a tumor regrowth in the Lt. sphenoid ridge and Lt. periorbital space. A second craniotomy was performed on March 25, 2008. The tumor was partially resected. Histological examination from second operation did not differ from those of the first operation. The diagnosis was transitional (mixed) type meningioma. The patient underwent 2nd GK radiosurgery for the residual tumor on July 2, 2008. The tumor volume was 19.8cc and radiation dose was 9.9Gy at 55% marginal dose. The patient was admitted in November 10, 2008 with headache, severe Lt. eyeball pain, Lt. facial palsy. MR imaging demonstrated a rapid regrowth of residual tumor(about 84x47x43mm), involving the Lt. cavernous sinus, Lt. sella fossa, Lt. Meckel''s cave, with prominent anterior, posterior extension to the Lt. deep orbital space, Lt. CPA cisternal space, compression to the pons, cisternal cranial nerves(including Lt. facial nerve), mild parenchymal edema(at the Lt. middle cerebellar peduncle), and encasement of Lt. cavernous, distal ICA - aggravated state, associated with suggested atypical change.
The patient did not undergo reoperation for tumor removal. Because the patient''s condition was very poor with septic pneumonia, she died at February 19, 2009 from sepsis.
This is a retrospective study.
The peripheral portion of the tumor which received a relatively low radiation dose (9.9 Gy) because of repeated GK radiosurgery grew rapidly during 4 months after GK radiosurgery.
This suggests that a radiation dose may not be sufficient for control of residual tumor and/or tumor may be change to malignant. Project Roles:
P. Moon ()