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Commentary
Brainstem Ganglioglioma
from the medulla oblongata to C3, accompanied by syringomyelia. All our patients were operated on. Total resection was achieved in 2 cases and partial resection in one. In our opinion, even if the neoplasm is adherent to the medulla and lower cranial nerves, with care, it can still be totally resected. In one of our cases, the tumor was hard, surrounded the PICA, and was partially located lateral to the medulla; therefore, a partial resection only was performed. This patient suffered intraoperative respiratory arrest, but recovered quickly. All three patients developed transient neurological deficits after surgery. Two patients had temporary tracheotomies. In the two cases in which the tumor was totally resected, most neurological deficits had resolved by the time of discharge from the hospital, and both returned to their normal work. The patient who underwent partial resection still had some deficits, including hoarseness, dysphagia, and disturbance of coordination, 40 months after surgery. In the study by Dr. Lagares et al., all of the patients underwent partial resection. The longest follow-up period was 10 years; in that time, no growth of the tumor remnant was noted on MRI. Because of this, the authors suggest that partial resection is an acceptable treatment strategy for brainstem ganglioglioma. Effective surgery can not only relieve clinical symptoms, but can also produce a good long-term outcome. Based on our experience, we prefer to minimize damage to normal tissue and vessels during surgery, which is the key to decreasing morbidity and improving prognosis. Chung-cheng Wang, M.D. Beijing Neurosurgical Institute Beijing, China The authors have put a great deal of time, effort, and thought into describing these cases. They have done a very good pathological study in terms of the light microscopy. Unfortunately, from a clinical perspective, these cases are really not helpful in terms of providing any new information or insights into management. In the first place, three cases is a very small number. Perhaps more significantly, the MRI illustrations provided quite clearly demonstrate that these tumors are dorsal exophytic brainstem tumors, which have been well-known entities for at least two decades. There is a wide spectrum of pathology among these tumors, and gangliogliomas are certainly recognized as one of them. The surgical results in these cases were very poor, and this is another thing that is somewhat
Surg Neurol 323 2001;56:315–24
difficult to explain. Tumors with this appearance after subtotal resection should have relatively low morbidity and for this reason, the authors’ conclusion that radical surgery is probably not indicated because of the perioperative morbidity is not appropriate, given current techniques and current neurosurgical reality. The workup of the patients included angiography, which is something else that need not be done. Fred J. Epstein, M.D. Pediatric Neurosurgery Beth Israel Medical Center New York, New York Brainstem gangliogliomas, and particularly gangliogliomas, belong to a rare group of tumors. Fibrillary and pyloid astrocytomas and glioblastomas constitute the majority of them. That is why this description of three cases of brainstem gangliogliomas is interesting. It is unfortunate that the authors did not include important details of the intraoperative situations the surgeon might encounter, and did not discuss the role of monitoring of brainstem functions during removal of these tumors. The most important conclusion one can derive from this work is that despite the clear borderline visible on CT and MR images, these tumors can cause serious complications and considerable aggravation of the symptoms of the brainstem lesion. Considering this, partial removal of these tumors seems to be quite reasonable, and may be the treatment of choice. Based on our experience, total removal of these tumors is extremely risky. Of the 256 patients who have undergone surgery for brainstem tumors at our institution, 4 of them had gangliogliomas. Three of these patients were less than 16 years old. Routine preoperative CT and MRI with contrast enhancement revealed a well-delineated lesion, with heterogeneous contrast enhancement. The bulk of the tumor was located in the fourth ventricle. There was no distinct borderline between the tumor and the brainstem. The tumor had a heterogeneous appearance, with some areas being welldifferentiated, yellow and with a solid consistency. There were also some portions of the tumor that were similar in color and structure to the brainstem tissue. However, histological studies revealed only tumor tissue, thereby disproving one surgeon’s suggestion of diffuse growth of the tumor. Surgical outcomes were unsatisfactory: two patients died after surgery and one experienced aggravation of his neurological symptoms. These results are notably worse than in cases of removal of
from the medulla oblongata to C3, accompanied by syringomyelia. All our patients were operated on. Total resection was achieved in 2 cases and partial resection in one. In our opinion, even if the neoplasm is adherent to the medulla and lower cranial nerves, with care, it can still be totally resected. In one of our cases, the tumor was hard, surrounded the PICA, and was partially located lateral to the medulla; therefore, a partial resection only was performed. This patient suffered intraoperative respiratory arrest, but recovered quickly. All three patients developed transient neurological deficits after surgery. Two patients had temporary tracheotomies. In the two cases in which the tumor was totally resected, most neurological deficits had resolved by the time of discharge from the hospital, and both returned to their normal work. The patient who underwent partial resection still had some deficits, including hoarseness, dysphagia, and disturbance of coordination, 40 months after surgery. In the study by Dr. Lagares et al., all of the patients underwent partial resection. The longest follow-up period was 10 years; in that time, no growth of the tumor remnant was noted on MRI. Because of this, the authors suggest that partial resection is an acceptable treatment strategy for brainstem ganglioglioma. Effective surgery can not only relieve clinical symptoms, but can also produce a good long-term outcome. Based on our experience, we prefer to minimize damage to normal tissue and vessels during surgery, which is the key to decreasing morbidity and improving prognosis. Chung-cheng Wang, M.D. Beijing Neurosurgical Institute Beijing, China The authors have put a great deal of time, effort, and thought into describing these cases. They have done a very good pathological study in terms of the light microscopy. Unfortunately, from a clinical perspective, these cases are really not helpful in terms of providing any new information or insights into management. In the first place, three cases is a very small number. Perhaps more significantly, the MRI illustrations provided quite clearly demonstrate that these tumors are dorsal exophytic brainstem tumors, which have been well-known entities for at least two decades. There is a wide spectrum of pathology among these tumors, and gangliogliomas are certainly recognized as one of them. The surgical results in these cases were very poor, and this is another thing that is somewhat
Surg Neurol 323 2001;56:315–24
difficult to explain. Tumors with this appearance after subtotal resection should have relatively low morbidity and for this reason, the authors’ conclusion that radical surgery is probably not indicated because of the perioperative morbidity is not appropriate, given current techniques and current neurosurgical reality. The workup of the patients included angiography, which is something else that need not be done. Fred J. Epstein, M.D. Pediatric Neurosurgery Beth Israel Medical Center New York, New York Brainstem gangliogliomas, and particularly gangliogliomas, belong to a rare group of tumors. Fibrillary and pyloid astrocytomas and glioblastomas constitute the majority of them. That is why this description of three cases of brainstem gangliogliomas is interesting. It is unfortunate that the authors did not include important details of the intraoperative situations the surgeon might encounter, and did not discuss the role of monitoring of brainstem functions during removal of these tumors. The most important conclusion one can derive from this work is that despite the clear borderline visible on CT and MR images, these tumors can cause serious complications and considerable aggravation of the symptoms of the brainstem lesion. Considering this, partial removal of these tumors seems to be quite reasonable, and may be the treatment of choice. Based on our experience, total removal of these tumors is extremely risky. Of the 256 patients who have undergone surgery for brainstem tumors at our institution, 4 of them had gangliogliomas. Three of these patients were less than 16 years old. Routine preoperative CT and MRI with contrast enhancement revealed a well-delineated lesion, with heterogeneous contrast enhancement. The bulk of the tumor was located in the fourth ventricle. There was no distinct borderline between the tumor and the brainstem. The tumor had a heterogeneous appearance, with some areas being welldifferentiated, yellow and with a solid consistency. There were also some portions of the tumor that were similar in color and structure to the brainstem tissue. However, histological studies revealed only tumor tissue, thereby disproving one surgeon’s suggestion of diffuse growth of the tumor. Surgical outcomes were unsatisfactory: two patients died after surgery and one experienced aggravation of his neurological symptoms. These results are notably worse than in cases of removal of