Gliomas of the Chiasm and the Third Ventricle Bottom: Clinical Peculiarities and Combined Treatment

A.N. Konovalov, S.K. Gorelyshev, I.K. Serova, V.I. Ozerova, V.A. Krymsky, N.A. Mazerkina, A.G. Korshunov

(Burdenko Research Institute of Neurosurgery, Moscow)

The study is based on the analysis of 319 cases with gliomas of the chiasm and the third ventricle bottom, who were treated at the Burdenko Research Institute of Neurosurgery in 1982-2001. These gliomas are a heterogeneous group of tumors (exophytic and endophytic neoplasms), which differ in their clinical manifestation and indications for this or that type of treatment.

Exophytic tumors (276 cases) had a marked asymmetric nodal growth and a progradient course. They were characterized by asymmetric vision disorders and hypertensive syndromes, watched against a background of minor endocrine disturbances. Tumor topography, peculiarities of a clinical picture and necessity of applying a definite approach for its removal were dependent on a place of a tumor origin and its location in one of the segments of an optic tract: an intracranial segment of the optic nerve and an anterior angle of the chiasm, its middle segment, its posterior segment, an optic tract and a hypothalamic part of the third ventricle bottom.

У 216 больных было произведено хирургическое удаление опухоли (в 18% случаев практически полное, в 25% – субтотальное, 57% – частичное). Общая послеоперационная летальность составила 8%, однако в течение последних 7 лет летальных исходов не наблюдалось. Рецидивы возникли у 25% больных (при наблюдении от 1 до 16 лет, среднее – 6,7 лет). Хирургическое удаление опухоли является эффективным методом лечения, и, как первый этап, показано у всех больных с экзофитными глиомами. Послеоперационный период протекает без осложнений у подавляющего большинства больных. Наиболее частыми причинами осложнений являются: гематома и месте удаленной опухоли, гипоосмолярно-гипонатриемический синдром, нарастание гидроцефалии и субдуральные гидромы.

A tumor was removed in 216 patients (practically total removal -18%, subtotal removal – 25%, partial removal – 57% of cases). A rate of total postoperative mortality was 8%. However, there were no fatal outcomes during the last 7 years. Relapses were watched in 25% of cases (a follow-up period of 1-16 years; 6.7 years on the average). Tumor removal was an effective method of treatment. It was indicated as the first stage in all the patients with exophytic gliomas. There were no postoperative complications in the majority of cases. The most frequent causes of complications were hematoma in the area of removed tumor, hypoosmolarity-hyponatriemia syndrome, hydrocephalus aggravation and subdural hydromas.

As for a remote period, there was improvement of visual functions in 28% of cases; they did not improve in 48% of patients. We did not watch any considerable effect on a height of children, their sexual development and neurosecretion; however, there were some cases with marked obesity and progenesis.

The main factors, reducing probability of a prolonged growth of tumor, were as follows: its total removal, radiotherapy and presence of degenerative changes within a tumor. Radiotherapy, indicated in partial removal, was irrespective of proliferation of vascular endothelium, Its carrying out in anaplastic astrocytomas was not dependent on removal efficacy. A repeated operation with subsequent radiotherapy was a method of choice in treatment of relapses. It was performed even in case of no augmentation of clinical symptoms by that time.

Endophytic tumors of optic tracts (43 cases) were characterized by an infiltrative growth in relation to them, bilateral localization in a half of cases, presence of neurofibromatosis-1, appearance of symptoms in early childhood, acceleration of sexual development, their higher rate in girls (a ratio of 2:1), presence of congenital developmental abnormalities. It should be emphasized, that surgical treatment of endophytic tumors is contraindicated. A follow-up and MR examinations with enhancement are necessary. When there are signs of a prolonged growth, radiation therapy is recommended in children of not more than 4 years old.