The next presenter, Dr. Asim Skomorac, Surgery of Posterior Fossa Tumors, Our Experience, is Chairman of Neurosurgery in Zenica, Bosnia and Herzegovina. Ladies and gentlemen, first of all I would like to thank organizing committee for inviting me here and to give me opportunity to give a speech. I would like to present our humble experience in treating of posterior fossa tumors. I'm coming from the small neurosurgical unit with 12 beds and our hospital is covering the region of the 400,000 inhabitants. As we all well know, posterior cranial fossa is a part of cranial cavity located between foramen, magnum and retorium cerebelli. It contains brain stem, fourth ventricle and cerebellum. There are numerous classification of the tumors, but one of this is given by this colleague, Behang Amini. Approximately 75% of brain tumors are ill children. Ill children are localized in posterior cranial fossa, while 15 to 20% of brain tumors in adults are in posterior fossa. Pathological characteristics of these tumors are diverse. Prognosis ranges from promising to disappointing, depending on the histopathological findings, degrees of surgical resection and other therapy. Great technological advancements have led to clearer understanding of tumor biology, image features, surgical techniques, chemotherapy, radiation protocols and all of this led to prolonged survival. Clinical representation, of course, is determined by three basic factors, localization, histological form, and CSF disturbance. Essentially, tumor can act in two basic ways, increase intracranial pressure or have direct compression of posterior fossa structures. Symptoms of elevated cranial pressure include well-known symptoms. Diagnosis can be made by neurological examination, CT with or without contrast, and MRI without contrast. Therapy, of course, first line of therapy is surgery. That can be followed by the chemotherapy, radiotherapy. In our respective study included 47 patients with posterior fossa tumors who were treated at our department. Surgical approaches were tailored to tumor localization and all PCA tumors were treated by retrocyclic approach. We analyzed the age and gender of patients, initial symptoms, extent of removal, tumor localization, preoperative and postoperative findings, neurological findings, and histopathological findings. Total number of brain tumor surgeries were in this period 367 and out of these 47 were surgeries for posterior fossa tumors. There was slight male prevalence for 53.2%. One of the cases, male, 49 years, preoperatively headaches, gross total removal, PhD, vestibular schwannoma, postoperatively facial paralysis. In age distribution we have dominance in ages 50 to 65 and there was seven pediatric tumors. Another case, male patient, 53 years, headaches, vomiting, PhD, it was meta from the lung, gross total removal, and postoperative clinical improvement. Initial signs and symptoms were different, dominating headache, nausea, vomiting, and hearing disturbances, vertigo, ataxia, and some facial paresthesia. Another case, female, 59 years old, headache and vertigo, hypoecousia, preoperatively gross total removal, it wasn't gross total removal, we left part in the intracanular part, PhD, schwannoma, postoperatively she was much better. Preoperative neurological findings dominated cerebellar syndrome and for localization we can say that most of the tumors were in the cerebellum, and then PCA, tumors, brainstem, and intraventricular. Another case, female, 60 years old, headache, cerebellar syndrome, gross total removal, PhD, schwannoma, postoperatively neurologically intact. We were able to preserve facial function. Accident of removal, more than 50% of patients we were able to do total resection, subtotal resection in almost 50% of cases, reduction in almost 30%, and biopsy in only 2%. Another patient, female, 63 years old, headache, cerebellar syndrome, preoperatively facial paralysis, PhD, schwannoma. There was attempted removal during the surgery, there was malignant edema of the cerebellum and she dies 3 days after surgery. Histopathology, most of the tumors were, in accordance with the literature, metastasis was dominating, 45% of tumors were metastatic, and the next one was schwannoma. There was also pylocytic astrocytoma, ependymoma, hemangioblastoma, medulloblastoma, or GBM. One of the recent cases, male, 50 years old, facial paresthesia and hyperacusia. Preoperatively, subtotal removal, PhD, schwannoma. Postoperatively, clinical improvement, we were able to preserve facial function. Postoperatively, in 30% we achieved some neurological improvement. In more than 15% of cases we have a change in status. Deterioration was in 10.6% and there was 2 patients were dead, one, as I showed before, and the other patient that died, there was metastatic tumor of the cerebellum and he died the day before the discharge. There wasn't autopsy, we suspect it was thromboembolic event. There are some hemispheric tumors. Female, 53 years old, headache, vomiting, cerebral syndrome, gross total removal, metastatic tumor from the breast, postoperatively clinical improvement. Female, 16 years, headache and deterioration of consciousness to supper, gross total removal, polycystic gastrocytoma, postoperatively clinical improvement. Another case, female, 8 years old, headache, vomiting, cerebral syndrome, subtotal resection, polycystic gastrocytoma, postoperatively clinical improvement. Another patient, male, 38 years old, headache, vomiting, vertigo, reduction of tumor, post-epidemic grade 2, postoperatively clinical improvement. In conclusion, we can say that posterior fossil tumors are very difficult medical problems for the patient and a great challenge for the surgeon. The process of treatment of such patient is improving the quality of life, prolonging the survival and cure, if possible, and role of neurosurgeons. In neurosurgery, this process is the optimal resection of the tumor without endangering the neurostatus and the general state of the patients. Thank you very much for your attention. Thank you. Thank you very much, Dr. Skomorac, for your beautiful and honest presentations. For you who don't know, Zenica was also a third city in Bosnia, and it is one of the very heavily impacted cities during the war, and Dr. Skomorac was leading the effort to rebuild the medical practice and neurosurgery practice in this city, and I appreciate very much what he did. Any questions from the audience, comments, or discussion? I have a question. You know, it's known that patients with cystic vestibular schwannomas are much more difficult to radically resect than the patient with solid schwannomas, and you showed several of both types. What is your experience, and do you have any tips or suggestions during resection as to resection difficulties and stuff like that? Yes, I agree. One thing is that I think all the vestibular schwannomas are gigantic, and more than 40 centimeters, and that's true that cystic vestibular schwannomas are more difficult to remove. So I'm not sure how much I can judge it because it's a small series, but I agree totally with you. Dr. Omefti. I know the experience and the literature keep repeating the same things you just said, that the cystic vestibular schwannomas is more difficult, and we heard earlier presentation of the worse of the acoustic. You saw every one of them and their old cystic, and I would like to hear Dr. Omefti, what's his experience with them. But I think they are, if you do not understand the pathoanatomy of the cystic. When you have a solid one, then you have an arachnoid plane to dissect between the structure and the tumor. When that becomes cystic, then the wall of the tumor is the wall of the cyst. It's against that arachnoid plane, which makes it a little bit difficult to separate because you could miss it all and you come outside it. I think by recognizing that the cyst of the wall is inside the arachnoid, the plane is still, although it's not the things. The outcome for me, it hasn't been that different. I know this is hanging in the literature, and a lot of people kind of feel that way, but cystic has not been a worse outcome for me than cystic. Are you suggesting that we should leave the cyst alone during resection, Dr. Omefti, and behave as a cyst part, integral part of the solid part of the tumor? No, you have to recognize now that the cyst wall, it's a two-membrane. It's the tumor membrane, and that's the cyst wall, and the regular arachnoid. Frequently those separated, thinking that this is the plane and you're outside the cyst already and outside the arachnoid and into the nerve. It's to realize that there is a very thin wall, which is the tumor, and there is a very thin wall, which is the regular arachnoid, and those two are all membrane are together, and you need to work between those two membrane. Thank you.

posterior fossa tumors

tumor classification

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chemotherapy

radiotherapy