Neurology India Medknow Publications on behalf of the Neurological Society of India ISSN: 0028-3886 EISSN: 1998-4022 Vol. 51, Num. 3, 2003, pp. 379-382

Neurology India, Vol. 51, No. 3, July, 2003, pp. 379-382

Choroid plexus papilloma of the posterior third ventricle during infancy & childhood: Report of two cases with management morbidities

Pawar SJ, Sharma RR, Mahapatra AK, Lad SD, Musa MM
The National Neurosurgical Centre, Khoula Hospital, Post Box 90, Postal Code 116, Mina-Al-Fahal,

Correspondence Address:
P.O.Box 397, Postal Code 118, Al-Harthy Complex, Muscat
rrsharma@omantel.net.om

Code Number: ni03123

ABSTRACT

We report two cases of posterior third ventricular choroid plexus papilloma, one in an 8-month-old infant and another in a two-year-old child. These cases presented with features of obstructive hydrocephalus. Both these patients underwent a ventriculo-peritoneal (VP) shunt surgery prior to the tumor excision. Following the VP shunt surgery both patients developed ascitis requiring exteriorization of the abdominal end of the shunt. There was a clear proof of CSF overproduction: 1400-1500 ml/ day in the eight-month-old infant and 900-1200 ml / day in the two-year-old child. In the former it was transient and could be treated with revision of the VP shunt whereas in the second case a ventriculo-arterial shunt had to be done. In the second case a staged reduction cranioplasty was also performed for an enormously enlarged head (head circumference—74 cm). Interesting clinical and radiological findings and useful management strategies are described.

INTRODUCTION

Tumors of the choroid plexus, including the benign and malignant varieties, constitute less than 1% of the total spectrum of intracranial tumors. Amongst these, those arising from the third ventricle are uncommon.[1],[2],[3],[4],[5],[6] There are only a few reports of choroid plexus papillomas arising from the posterior third ventricle.[7] We describe two cases of choroid plexus papilloma of the posterior third ventricle, which presented with features of obstructive hydrocephalus. In both cases the CSF diversion procedures were followed by microsurgical excision. Interestingly, in both cases, the CSF production in excess of 1 liter per day posed special difficulty in the management.

CASE REPORTS

Case 1
An 8-month-old apparently healthy female infant was admitted with progressively increasing drowsiness of one-week duration. The infant was drowsy and there was bilateral papilledema. The anterior fontanelle was tense and the head circumference was 48 cm. Systemic examination was unremarkable. Computerized tomography (CT) scan of the brain revealed gross dilation of both the lateral ventricles and a large enhancing mass in the posterior third ventricle [Figure-1]. Digital subtraction angiography (DSA) showed a highly vascular third ventricular tumor, supplied by dilated and elongated medial posterior choroidal arteries.

As a first stage management, a ventriculo-peritoneal (VP) shunt was carried out following which the child's general condition improved remarkably. The parents did not agree upon any further surgical intervention.

After a gap of 8 weeks the child was readmitted with gross ascitis and deterioration in her level of sensorium. The peritoneal end of the VP shunt tube was exteriorized to control the ascitis. This showed about 1400-1500 ml/day of cerebrospinal fluid (CSF) drainage. After correction of the fluid and electrolyte imbalance, the drainage height was gradually raised to 10 cm to control the CSF output to around 200-ml/day and a week following the exteriorization of the shunt, the shunt system was revised. Within a couple of weeks, the child became asymptomatic and the ascitis subsided totally. A CT brain scan at that time showed good decompression of the lateral ventricles. A definitive surgery was then carried out via the trans-callosal route through the enlarged right foramen of Monro. The bright pink vascular tumor was microsurgically excised in total. The postoperative course was uneventful and one week later the patient was discharged. The histopathology revealed papillary structure lined by uniform cuboidal epithelium suggestive of choroid plexus papilloma. There was no evidence of malignancy.

At the follow-up after 4 weeks the CT scan was repeated which showed bilateral subdural hygromas with minimal mass effect. However, these spontaneously regressed within 6 weeks as seen on the subsequent CT scans. At the last follow-up 8 years following surgery, the child was neurologically normal.

Case 2
A 2-year-old male child, the only issue of a consanguineously married couple, was admitted with a history of progressively enlarging head since early neonatal period. The head size increased remarkably in the last 6 months. The CT scan performed at the age of six months had shown gross hydrocephalus [Figure-2a]. An ultrasound scanning at the age of 2 years showed a third ventricular tumor with a gross hydrocephalus. The CT brain scans at this stage showed an iso-atteneuation lesion in the third ventricle on the plain study, which brilliantly enhanced on contrast administration [Figure-2b]. The head circumference was 74 cm. The child had upward gaze palsy with a typical sunset sign. The anterior fontanelle was tense and the scalp veins engorged. There were wide sutural separations and the child was unable to hold his head. He could not sit himself nor could he roll in bed.

A repeat CT brain scan revealed an iso-attenuation lesion at the region of the posterior third ventricle with significant enhancement on contrast administration with a papery thin cerebral cortex and grossly dilated lateral and third ventricles. A part of the lesion was entering anteriorly into the foramen of Monro but a large part was present in the quadrigeminal plate cistern. The child underwent a VP shunt as a first stage procedure to relieve the hydrocephalus. In the following week, the tumor was approached via the supracerebellar route. The tumor in the quadrigeminal plate cistern was highly vascular in nature. Due to high vascularity and frequent cardiac changes during microsurgery, only a subtotal excision of the tumor was possible. However, the postoperative course was uneventful. The head circumference had come down to 68 cm. The parietal bones were overriding the frontal bones and there was some recovery of the cerebral mantle. Periodic magnetic resonance imaging (MRI) of the brain showed the residual part of the tumor along with the presence of bilateral subdural collections [Figure-3a] and [Figure-3b]. The lateral ventricles were smaller as compared to the earlier preoperative scans.

The histopathological study showed that the tumor was composed of thin delicate papillae, covered by a layer of tall columnar cells [Figure-4]. The findings were suggestive of choroid plexus papilloma.

After a gap of 4 months the child was readmitted only for an elective reduction cranioplasty, as the parents did not agree for further microsurgical excision of the residual tumor. Under general anesthesia he was subjected to bifrontal and biparietal reduction craniectomies. The overriding frontal and parietal bones were partially corrected; and the residual bilateral subdural collections were drained. The postoperative course was uneventful and he was discharged shortly. A repeat CT scan brain three months following the last surgery showed gross reduction in the amount of residual bilateral subdural hematomas, well-decompressed ventricles and the residual tumor. This time the over-riding antero-medial parts of the parietal bones on both sides were excised. Free island flaps were created which were fixed with miniplates and screws. A repeat CT scan showed well-decompressed ventricles.

After an uneventful period of one week the child was noted to have abdominal distension. Ultrasound study revealed a large amount of free fluid in the abdominal cavity. Abdominal tapping was performed on two separate occasions to drain around 250 ml of clear fluid but within 24 hours the abdominal distension reappeared. The peritoneal end of the VP shunt was therefore exteriorized to drain CSF. The daily volume of CSF drained ranged between 900 and 1200 ml. With this intervention the ascitis progressively subsided and all the biochemical parameters were settled within the next two weeks. The daily CSF volume however did not decrease despite increasing the drainage height to 10 cm. The exteriorized VP shunt was removed and a fresh ventriculo-atrial (VA) shunt was performed. After a further two-week hospital stay, the patient was discharged. At the time of discharge, the head circumference was 48 cm. The parents did not agree for further surgical intervention for the excision of the residual third ventricular lesion. However, the upward gaze palsy improved, the sunset sign disappeared and the child could sit himself and hold the head. The child was then lost to further follow-up.

DISCUSSION

Choroid plexus papillomas are a variety of congenital intracranial tumors of neuroectodermal origin. They constitute about 1% of the total spectrum of central nervous system tumors.[1],[2],[5],[7],[8],[9] The most frequent site of occurrence is the lateral ventricles and sometimes they are multiple in nature.[1],[9],[10] Among these tumors those originating in the region of the third ventricle are very rare[3],[4],[5],[6],[7],[11],[12],[13],[14],[15],[16],[17] A small-size tumor in the third ventricle is likely to be missed at a very early stage.[9] Interestingly, Adra et al[18] have described a case of third ventricular choroid plexus papilloma diagnosed at 33 weeks of gestation. As the patient grows older, the presentation usually includes visual impairment and gait disturbances, due to the effects of raised intracranial pressure and direct pressure of the tumor.[3],[12],[19] Hydrocephalus is mostly the result of two mechanisms. One mechanism is related to the direct obstruction of the cerebrospinal fluid (CSF) pathway i.e. blocking the foramen of Monro or the aqueduct of Sylvius and occasionally obstruction of the subarachnoid spaces.[15],[20] The other equally important mechanism is that of CSF overproduction due to the tumor activity itself.[21],[22] The normal CSF production (0.29-0.35 ml / minute) is increased manifold in cases of choroid plexus papilloma, resulting in a rapid development of hydrocephalus[11],[13],[17],[19],[20] as happened in our cases (0.66 to 1 ml / minute). This also proves that these tumors maintain normal physiological function of the choroid plexus. The majority of these tumors are diagnosed in the neonate or in early childhood period, depending upon the severity of the hydrocephalus.[3],[4],[9],[16],[23] This indicates their congenital origin. Occasionally, the tumors are detected in the older age group.[1], [2],[11],[14],[15]

Pollack et al[17] described an interesting case of a cystic choroid plexus papilloma of the third ventricle in a 2-year-old child, who presented with bobble-head-doll syndrome and drop attacks. The highly mobile nature of this cystic tumor was causing intermittent impaction of the foramen of Monro and the proximal aqueduct leading to intermittent head tilt and bobble-head symptoms, which completely subsided after the excision of the tumor.

Behavioral changes, as the presenting symptoms of the third ventricular choroid plexus papilloma, are uncommon. Close proximity and pressure over the hypothalamus might have been responsible for the psychosis and behavioral changes, which subsided gradually following a total excision of the tumor.

As the majority of these cases present with hydrocephalus of various degrees, the insertion of a shunt system for diversion of the CSF has been established as a primary step. Efforts are then made for a total tumor excision, as the choroid plexus papilloma is a benign pathology. Raimondi et al,[24] in their series of 22 cases of choroid plexus papilloma of various ventricular locations except the posterior third ventricle, strongly recommended a total removal of the lesion, irrespective of the site of origin. Though the recent microsurgical techniques have improved the overall outcome, individual cases may show a different picture. The surgical route depends upon the location of the tumor.

Other modes of treatment include a trial of radiosurgery as suggested by Duke et al. Radiosurgery might have been responsible for slow occlusion of the feeding vessels, finally resulting in avascular necrosis and reduction in the tumor volume.

The postoperative collapse of the thin cerebral cortical mantle and development of subdural collections are other common findings[3],[5],[16],[19] that were seen in both our cases. By and large the subdural collections do not require operative intervention and in the subsequent CT scans, progressive reduction in the size of subdural collections may be found.

Our second patient had an enormously enlarged head to start with (74 cm). After the shunt and a partial excision of the tumor, the head circumference reduced (68 cm), however, the reduction was not significant. Nursing and daily management of the patient was difficult due to the large head, which prompted a staged reduction cranioplasty. This was performed in two stages and the head circumference could be brought down to 48 cm, which was quite reasonable for the child as he could hold his head. A reduction cranioplasty procedure may prove useful and safe to reduce the size of the head as well as to minimize the occurrence of subdural collections. Also this helps in better nursing care of these patients with a large head.

REFERENCES

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