=Acta N uroch rurg ca

Acta Neurochir (Wien) (1992): 116: 137-146

9 Springer-Verlag 1992 Printed in Austria

Treatment of Tumours of the Pineal Region and Posterior Part of the Third Ventricle* H.-D. Herrmann, D. Winkler, and M. Westphal Department of Neurosurgery, University Hamburg (UKE), Hamburg, Federal Republic of Germany

Summary The evaluation of tumours located in the posterior part of the third ventricle or pineal region is achieved best by magnet resonance imaging (MRI). It shows the exact localization and extent, the involvement ofneighbouring structures fike thalamus or quadrigeminal plate and the displacement of the large veins, the internal cerebral veins, the vein of Galen and the veins of Rosenthal. If only CT is available, angiography shoud be performed prior to operation to identify the course of the veins. In children with a pineal region tumour the "tumour markers" AFP and [3-HCG should be determined before operation. We approach the rare tumours entirely located within the posterior part of the third ventricle by the posterior interhemispheric transcallosal route with the patient in prone position with the head elevated. The same approach is used for pineal region tumours extending above the internal cerebral veins. Tumours arising from the posterior thalamus extending into the thalamus and ventricle as well, are better approached by the posterior transcorticat transventricular route since the lateral view is rather limited by the midline approach. The most frequent tumours in the pineal region are approached if they are located below the internal veins by the infratentorial, supracerebellar route in the sitting position. A total of 60 cases are evaluted. If AFP and/or ~-HCG are positive a highly malignant nongerminomatous germ-cell tumour must be suspected. We recommend initial chemotherapy with a combination of Vinblastine, Ifosfamide and Cis-platin without biopsy to avoid tumour seeding. After the "markers" are normalized operative removal of the residual turnour and radiotherapy should be carried out. In a series of 13 children operated on for pineal region tumours a rigid neuropsychological and endocrine evaluation was perfomed with encouraging results. During the last 10 years we have performed 49 open operations and 11 stereotactic biopsies. 40% of the patients were children under the age of l 8.40% of the tumours in childhood and 60% in adults were benign. In childhood 24% were germinomas and 20% non-germinomatous germ cell tumours. * Invited Lecture presented at the European Congress of Neurosurgery, Moscow, June 23-29, 1991

The indications for stereotactic biopsy and for open operation after biobsy are discussed. Keywords: Posterior third ventricle tumonrs; pineal tumours; management; operative indication; technique; chemotherapy; results.

Introduction T u m o u r s are r a r e l y l o c a t e d in the p o s t e r i o r p a r t o f the t h i r d ventricle. M a s s e s l o c a t e d entirely within the ventricle u s u a l l y arise f r o m the c h o r o i d plexus like metastases, plexus p a p i l l o m a o r the rare m e n i n g i o m a . M o r e frequently the t u m o u r s arise f o r m the p o s t e r i o r t h a l a m u s a n d e x p a n d f u r t h e r into its lateral structures as well as the ventricle. T h e m o s t frequent localization, however, is the pineal region, the a r e a b e l o w the vein o f G a l e n a n d the i n t e r n a l cerebral veins, a b o v e the q u a d r i g e m i n a l plate, between the veins o f R o s e n t h a l . These t u m o u r s extend into the p o s t e r i o r p a r t o f the t h i r d ventricle a n d can involve the lateral p o s t e r i o r t h a l a m u s . T h e d i a g n o s t i c p r o c e d u r e s , the o p e r a t i v e app r o a c h e s the i n d i c a t i o n a n d j u s t i f i c a t i o n for o p e r a t i o n a n d stereotactic b i o b s y as p r a c t i s e d b y the a u t h o r s are presented.

Diagnostic Procedures 1. C T A s the first investigation usually A C T - s c a n is performed. It shows the l o c a l i z a t i o n a n d extent o f the lesion. O n l y in rare cases o f m a t u r e t e r a t o m a w h e n b o n y a n d fatty structures are visible a n d in s o m e cases o f pilocytic a s t r o c y t o m a it is possible to p r e d i c t the histological diagnosis with s o m e accuracy. I f M R I is n o t available a n g i o g r a p h y s h o u l d be p e r f o r m e d p r i o r to o p e r a t i o n to s h o w the l o c a l i z a t i o n a n d d i s p l a c e m e n t o f the veins, a n d the arterial b l o o d supply.

138

H.-D. Herrmann el al.: Treatment of Tumours of the Pineal Region and Posterior Part of the Third Ventricle

2. M R / The exact location, the extent of the lesion, involvement o f neighbouring structures like thalamus or quadrigeminal plate and the displacement of the internal veins, the vein o f Galen and the veins o f Rosenthal are sufficiently visualized with this investigation. D u r i n g the last 4 years it was not f o u n d necessary to p e r f o r m additional angiography. Neither the nature o f the lesion nor the infiltration can be diagnosed with reliable accuracy.

m a r k e r o f recurrence. Placental alkaline phosphatase was claimed to be a marker for germinoma. The reliability is n o t yet proven and it must be considered that it can be elevated by a n u m b e r o f malignant tumours as well as by smoking. In 8/9 cases o f g e r m i n o m a in childhood we f o u n d the typical two-cell-type germinoma cells in the C S F supporting the diagnosis (F. J. Schulte et al. 1987).

Table 1. Markers in Pineal-Region-Tumours

3. T u m o u r M a r k e r s

Tumours

AFP

HCG

PLAP

The highly malignant n o n - g e r m i n o m a t o u s germ-cell tumours, the malignant teratoma, the yolk-sac-tumour, embryonal carcinoma and c h o r i o c a r c i n o m a can be diagnosed if alfa-Fetoprotein (AFP) a n d / o r [bhumanc h o r i o n g o n a t o t r o p i n ( b - H C G ) is positive and elevated (Table 1).

Germinoma Teratoma (immat.) Teratoma (mature) Yolk-sac-tumour embryonal Carcinoma Choriocarcinoma

(+ ) + + -

-/+ +

(+ )

I f these markers are positive they can serve as indicator for the radicality o f treatment and as an early

+ = > 50ng/ml PLAP = Placental alkaline phosphatase

Fig. 1. AET. 49 yrs. F.: Tumour entirely localized within the posterior third ventricle. Removed by interhemispheric transcallosal approach. Histol. metastasis

H.-D. Herrmann et al.: Treatment of Tumours of the Pineal Region and Posterior Part of the Third Ventricle

139

Operative Approaches

3. Tumours of the Pineal Region

There are many approaches to the posterior third ventricle and pineal region (Apuzzo, 1987). During the last 10 years we used only three: the posterior interhemispheric-transcallosal, the transcortical-transventricular, and the infratentorial-supracerebellar (Stein 1971) approach.

Pineal tumours are the most frequent in this region. If they are located below the internal cerebral veins they are approached by the infratentorial-supracerebellar (Fig. 4) route in the sitting position; if they extend above the veins and the corpus callosum (Fig. 5) they are operated on by the interhemispheric route. The infratentorial-supracerebellar approach (Fig. 6) has the advantage that the vein of Galen and the internal cerebral veins are completely visualized above as well as both veins of Rosenthal laterally. With slight retraction of the rostral portion of the cerbellar vermis the posterior colliculi of the quadrigeminal plate are visible and from there the entire quadrigeminal plate up to the posterior commissure can be dissected free. While dissecting the lateral surfaces of the turnout, care must be taken not to injure the veins of Rosenthal and the superior cerebellar arteries as well as branches to the quadrigeminal plate but to seperate the tumour feeding vessels. Dissecting the lateral turnout surface more rostrally the white shining structure of the lateral portion of the posterior commissure will appear. This gives us the rostral limit of the quadrigeminal plate. Now the tumour can be separated from the quadrigeminal plate, starting from the posterior colficilus to the posterior commissure. In many cases the intraventricular portion can be removed easily. If the tumour has invaded the lateral walls of the ventricle it can be removed with the COz-laser. This has the advantage of mimimal traumatisation since the resection can be done in discrete layers and under sufficient haemostasis of the small perforating vessels, difficult to coagulate by bipolar coagulation. From this exposure we can see the entire roof of the ventricle, the foramina of Monroe and the massa intermedia. The view, however is limited by the posterior commisure so that the posterior inferior portion of the ventricle cannot be seen directly, approximately below a plane from the commisure to the lower margin of the interthalamic connexus (Fig. 7). To inspect this region, particularly the entrance of the aq 2 ueduct, a mirror should be used. Blood clots can be removed and if tumour remnants are seen below the commisure they can be resected with some experience with the CO2-1aser and a highly polished metal mirror (Fig. 8) and a curved-tip suction-irrigation device.

1. Intraventricular Tumours (Fig. 1) Tumours located entirely within the posterior part of the third ventricle are rare. They are best approached by the interhemispheric-transcallosal route (Fig. 2 A). Since it is quite a long distance along the falx and through the corpus callosum into the ventricle, the lateral exposure is limited and could cause difficulties if the tumour extends into the posterior thalamus. If the turnout extends into the rostral part, anterior to the interthalamic mass, it also can be approached by the anterior transcallosal route. 2. Tumours of the Posterior Thalamus (Fig. 3 A) Tumours arising from the posterior thalamus and extending into the ventricle are best exposed by the homolateral transcortical-transventricular route. This approach offers the best exposure of the intrathalamic portion of the tumour for resection. We resected the pilocytic astrocytomas in this region with the aid of CO2-1aser attached to the microscope (Figs. 3 B, C).

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4. CSF-drainage Fig. 2. Operative approaches: A) Interhemispheric-transcallosal route. B) Transcortical-transventricular route

In all cases of intraventricular surgery an external ventricular drainage should be placed at the end of the operation. We pass the catheter directly through the

140

H.-D. Herrmann et al.: Treatment of Tumours of the Pineal Region and Posterior Part of the Third Ventricle

A

B

C

Fig. 3. AET. 4yrs. M.: Tumour of the posterior thalamus extending into the ventricle (A). Transcortical, transventricular laser resection, (B: postop.). Histol. pilocytic astrocytoma. MRI 4 years later (C)

H.-D. Herrmann et al.: Treatment of Tumours of the Pineal Region and Posterior Part of the Third Ventricle

A

141

8

Fig. 4. AET. 10 yrs. M.: Pineal region turnout. CT-scan (A) and MRI (B). MRI shows internal cerebral veins and vein of Galen as well as relation to quadrigeminal plate. From the images it could not be predicted whether the tumour had infiltrated the quarigeminal plate. It could be removed totally. Histol. pineoblastoma

A

8

Fig. 5. AET 12 yrs. M.: Pineal region tumour extending above the internal veins and corpus callosum (A). Interhemispheric-transcallosal resection (B: postop.) Histol. pinealoma

field of operation even in the supracerebellar approach, Such drainage is extremely important since rapid intraventricular pressure increase can develop due to ob-

struction of the aqueduct by blood clots, swelling and also because of pneumocephalus. Prior to this rigid management we have lost one patient due to an increase

142

H.-D. Herrmann et at.: Treatment of Tumours of the Pineal Region and Posterior Part of the Third Ventricle

Fig. 8. Highly polished metal mirrors for visualization of the posterior inferior portion to the ventricle,below the posterior commissure and indirect laser-resectionof tumour remnants in this region

Fig. 6. Infratentorial-supracerebellarapproach

1

//

Fig. 7. Limitation of the view (dotted line) to the lower portion of the third ventricleand aqueduct in intracranial pressure so rapid that there was no time to place a burr hole and drain the ventricle. The drainage remains on a level of 15 cm water until no overflow or pressure increase is registered over 24 hours. If a CSF-shunt was placed prior to the operation, which we try to avoid, it should be closed before the craniotomy by ligation or clipping of the catheter.

Steps of Management 1. Primary Chemotherapy After CT- or MRI-diagnosis of a pinealregion tumour particularly in children the ~ markers" alfa-fetoprotein (AFP) and beta-human chorion-gon-

atotropine (b-HCG) should be determined in serum and if possible in CSF. An elevation of one or both of these "markers" strongly supports the diagnosis of a higly malignant non-germinomatous germ-cell tumour. Since even a stereotactic biopsy can spread tumour cells into CSF causing diffuse tumour seeding one should rely on these markers and start with chemotherapy. We have applied the MAKAI-protocol, combining cisplatinum, Neomycin and VP-16, in 2 cases. In both cases the markers became negative after 2 blocks of chemotherapy and the control-MRI showed a significant reduction of the mass. The operation was then performed and the partially necrotic tumour removed. In both cases complete histological work-up revealed only "bening teratoma"; hence it can be assumed that chemotherapy had eliminated the malignant component. Cranio-spinal radiation therapy was given postoperatively. Both children are unimpaired and disease free for 1 and 1 72 years after therapy (Fig. 9).

2. Primary Radiation Therapy The reliability and specificity of PLAP as a "marker" for germinoma is not confirmed yet. I f P L A P is positive and other causes of increase can be ruled out, and if the "two-type-cells" can be found in the CSF, the probability of a germinoma is high enough for primary radiation therapy of the tumour region. After 15-20 gy, a CT or MRI should be performed. If the mass has not disappeared or at least considerably shrunk the diagnosis must be in doubt, the radiation therapy interrupted and the lesion removed surgically. In all other cases histological verification of the tumour must be achieved either by stereotactic biopsy or by open removal of the lesion.

k,

B Fig. 9. 12yrs M.: 6/1990: pineal region tumour (A: CT, B: MRI). b-HCG: 22 438 U/1 serum, 6 800 U/1 CSF. AFP: < 2.4U/1 serum, 3.9 U/1 CSF. Chemotherapy, MAKAI-protocol. 8/1990: b-HCG: 196U/1 serum. AFP neg. CT-scan preop. (C) Turnout resected. Histol. "benign" teratoma. Postoperative radiation therapy. 4/1991: CT-scan (D): Child disease free and unimpaired

144

H.-D. Herrmann eta[.: Treatment of Tumours of the Pineal Region and Posterior Part of the Third Ventricle

C

D Fig. 9

3. Stereotactic Biopsy Since 1982 we have performed stereotactic biopsies in tumours of the posterior part of the third ventricle

or pineal region only if multiple lesions are found, in lesions appearing diffusely infiltrating prohibiting a primary resection and in high risk patients. We found

H.-D. Herrmann etal.: Treatment of Tumours of the Pineal Region and Posterior Part of the Third Ventricle from our own experience that surgergy is indicated after stereotactic biopsy, if the biopsy did not yield a sufficiently reliable histological diagnosis, if the diagnosis was non-malignant tumour, pineocytoma, benign teratoma, pilocytic astrocytoma, or if the adjuvant, raditation therapy, based on biopsy diagnosis, e.g. germinoma, had not had the expected effect. There is no indication f o r open biopsy.

Results During the last 10 years we have operated on 60 patients with tumours of the pineal region. In 11 cases a stereotactic biopsy was performed. 40% of the entire series were children under the age of 18. An initial series of 13 consecutively cases of children operated upon between 1980 and 1986 were throughly re-evaluated 1 to 5 years after treatment for neurological and endocrinological deficits as well as for their psycho-intellectual development. In 10 cases no tumour remnants could be detected on postoperative CT-scans hence a total removal could be achieved. Children with germinoma, pineoblastoma and teratoma underwent craniospinal axis radiation postoperatively. None of the children died during treatment. The parents assessment of the quality of life (Table 2) was excellent or reasonable for all but two children. Of the two impaired children one was already damaged before treatment due to delay in diagnosis and the other had diffuse ventricular seeding of recurrence at the time of examination. One of these children was disabled by severe motor dysfunction, visual defects and convulsions. In two other children minor oculomotor dysfunctions were found, the others were free of neurological symptoms and signs. 4 children showed endocrinopathies: in three cases tumour associated panhypopituitarism persisted after Table2. Parent Assessment of Quality of Life Excellent General state of health Social contacts Intellectual function Motor function Follow-up n = 13

Reasonable

Poor

7

4

2*

8

3

2*

10

1

2*

3

7

3*

145

Table 3. Pathology of Pineal Region Tumours a) Benign tumours

Children

Adults

Astrocytoma Cavernoma Gangliocytoma Lipoma Meningioma Oligodendroglioma Pineal Cyst Pineocytoma Vascular turnout Unclassified

4 l

1

1 1 1 1 1 10 1 3

All

10

22

b) Malign tumours

Children

Adults

Astrocytoma Ependymoma (anapl.) Germinoma Medulloblastoma Metastasis Pineoblastoma PNET Teratorna All

1 3

3

6 1 2 1 5 15

14

treatment, only one child developed growth hormone and A D H deficiency following surgery and craniospinal axis radiation. The children were evaluated with a battery of 14 neuropsychological tests: Three children had no detectable abnormalities, 5 children showed only minor or moderate deficits, in 4 children the scores were below average (2 sigma), among these were the two children mentioned above. Generally verbal intelligence seemed to be about average, nonverbal intelligence and ability for concentration showed decreased scores. These rather satisfactory results encouraged us to continue the strategy of primary operation with the aim of total removal (Table 3). 40% of the tumours in childhood and 60% in adults were classified as benign. In the group of children 24% had germinomas and 20% non-germinomatous germ cell tumours. In the adult group 27% benign pineocytoms and only 10% of germinomas were found (Table 3). This distribution is somewhat different to that reported by Stein 1971, who had 1/3 malignant, 1/3 benign, and 1/3 germinomas, The results remained comparable to the first series. We had no mortality in the group of children. 4 adults died after operation caused by acute decom-

146

H.-D. Herrmann et aL: Treatment of Tumours of the Pineal Region and Posterior Part of the Third Ventricle

pensated hydrocephalus, severe diffuse brain swelling of unknown cause, acute extensive epidural haematoma supratentorially and a secondary haemorrhage into the resection area of a highly vascular pineoblastoma.

1. 2. 3. py is

if histology is uncertain if a "benign" tumour was diagnosed if no or not sufficient response to radiation theraencountered.

Conclusion

References

Tumours of the posterior portion of the third ventricle and pineal region can be resected in most cases totally with satisfactory results. The rather high proportion of"benign" tumours also supports the concept of primary open operation. Non-germinomatous germ cell tumours with positive "markers" should be treated with chemotherapy prior to operation. With few exceptions (positve PLAP and positive CSF-cytology) germinomas can only be diagnosed histologically. This can be achieved by stereotactic biopsy. After total resection of a germinoma a reduction of the focal radiation dose without cranio-spinal radiation should be considered. In our opinion stereotactic biopsy is indicated: 1. In older or high risk patients 2. In cases ofinvasive tumour growth into the thalamus or mesencephalon 3. in polytopic tumours If stereotactic biopsy has been performed with less rigid indications an open operation should be considered thereafter

I. Apuzzo MLJ (Ed) (1987) Surgery of the third ventricle. Williams and Wilkins, Baltimore 2. Herrmann HD, Schulte F J, Winkler D, Miiller D (1988) Tumoren der Pinealisregion im Kindesalter. In: Therapie prim/irer Hirntumoure. W. Zuckerschwerdt Verlag, pp. 371-374 3. McComb JG, Apuzzo MLJ (1987) Posterior interhemispheric retrocallosal and transcallosal approach. In: Apuzzo MLJ (ed) Surgery of the third ventricle. Williams and Wilkins, Baltimore, pp 611-641 4. Pendl G (1985) Pineal and midbrain lesion. Springer, Wien New York 5. Schulte FJ, Herrmann HD, Mfiller D etaL (1987) Pineal region tumours in childhood. Eur J Pediatr 146:233-245 6. Schulte FJ, Matthes-Martin S, Zarbock G, Herrmann HD (1987) Prognose und Lebensqualitgt nach Pinealis-Logen Tumoren im Kindesalter. Klin P/idiatr 199:429-439 7. Sugita K, Hongo K (1987) Posterior transcortical approach. In: Apuzzo MLJ (ed) Surgery of the third ventricle. Williams and Wilkins, Baltimore, pp 557-569 8. Stein BM (1971) The infratentorial supracerebellar approach to pineal lesions. J Neurosurg 35:19%202

Correspondence and Reprints: Dr. H.-D. Herrmann, Department of Neurosurgery, University Hamburg (UKE), D-W 2000 Hamburg, Federal Republic of Germany.