Giant choroid plexus papilloma of the lateral ventricle in fetus.

Choroid plexus papillomas (CPPs) are rare tumors having bimodal distribution. Pediatric CPPs are commonly present in supratentorial compartment and most commonly located in lateral ventricle and usually present at 16-18 months. Authors could find only one case report of fetal choroid plexus papilloma in the literature. In the present case, authors illustrate an unusual presentation of CPP with raised intracranial pressure (ICP) since birth, the need for proper preoperative planning, meticulous surgical technique, and intensive intra operative monitoring for normothermia, fluid-electrolyte balance, and blood replacement for achieving excellent results.

Introduction

Choroid plexus papillomas are considered as WHO grade I tumors and are among the most common tumors in children less than 2 years.[123] About half of them are located in the atrium of lateral ventricle. The median age at diagnosis is 18 months in case of lateral ventricle tumors. However the present case illustrates a case where the tumor was detected in-utero and had to be operated upon relatively early because of obstructive hydrocephalus and raised intracranial pressure with excellent outcome.

Case Report

This male infant was the first baby born to parents with non-consanguineous marriage, residing in a remote village. The prenatal period was uneventful except in 8th month of gestational age when a routine ultrasonographic (USG) examination revealed large head size, exact details were not available. Although the pregnancy was declared high risk, the baby was born at full term through Caeserian section.

At birth, the mother noticed large head size of the baby. Although the baby cried immediately after the birth he did not take feeds. In the next few days the baby had progressive increase in head size with excessive crying along with multiple episodes of vomiting.

He was brought to us at the age of 3 weeks with complaints of progressive increase in head size, episodes of excessive inconsolable cries associated with multiple vomiting as well as failure to gain weight. On examination, the anterior fontanelle was open and tense, head circumference was 52 cm. He was subjected immediately to non-contrast computerized tomography (NCCT) scan of the brain [Figure 1] that showed a large hyperdense mass lesion in the left lateral ventricle arising from the atrium causing biventricular obstructive hydrocephalus with enlargement of lateral ventricles. Contrast scan showed uniform enhancement in the lesion with multiple fronds-like structures. On three dimensional reconstruction it was clear that the lesion was arising from the left lateral ventricle choroid plexus wit h four well-defined stalks of attachments medially to the atrium. These radiological findings pointed towards choroid plexus papilloma (CPP) and he was planned for surgical excision of the lesion. In view of the complaints and features suggesting raised intracranial pressure since birth it was highly likely that the pathology was developed in fetal life and only when the problem became unbearable, parents sought medical advice.

Figure 1

Pre-operative non-contrast computerized tomographic scan-axial view

Patient was given general anesthesia and positioned prone and left sided parieto-occipital osteoplastic craniotomy was performed using MIDAS REX drill. Brain was tense on removing the bone flap, prophylactic cerebro spinal fluid (CSF) drainage from left frontal horn was performed to relax the brain. After this, duramater was opened and transcortical-transventricular approach was taken to the occipital horn of left lateral ventricle. Large, soft-firm, white-yellow colored, cauliflower-like lesion were seen that was could be partly sucked out. Under high-magnification microscope the feeders from the choroidal arteries were identified, coagulated and severed with minimal retraction of the lesion, utilizing the buoyancy provided by the CSF. Sequentially the other remaining stalks of attachments were identified microscopically and coagulated with bipolar electrocautery and cut. The complete lesion was excised in-toto [Figure 2] and the choroid plexus visible in the left lateral ventricle was coagulated. Hemostasis was achieved and closed with a ventricular drain placed in left lateral ventricle that was kept for 3 days. Surgery was uneventful and the infant was extubated next day.

Figure 2

Gross specimen of resected tumor

Post-operative period was uneventful. Anterior fontanelle became lax. Post-operative NCCT scan of the brain showed complete excision of the lesion with resolved hydrocephalus and accompanying interstitial edema [Figure 3]. The baby was discharged on post-operative day 10 and he was taking oral feeds with no further episodes of vomiting.

Figure 3

Post-operative non-contrast computerized tomographic scan

The infant was doing well at the last follow-up at 6 months post-operation. A post-operative Magnetic Resonance Imaging (MRI) brain revealed no evidence of residual lesion, resolution of hydrocephalus and evidence of corticectomy.

Discussion

CPP account for 2-5% of intracranial neoplastic lesions in pediatric age group. They are among the most common tumors in children younger than 2 years. When these lesions are located in the lateral ventricle, the median age at diagnosis is 18 months, and there is no predilection to occur in either sex. They are well-circumscribed lobulated intraventricular masses with cysts, necrosis, and hemorrhage. Microscopical fibrovascular connective tissue fronds, covered by cuboidal or columnar epithelium are seen. Mitotic activity, necrosis, and brain invasion are typically absent.

On immunohistochemistry they are positive for cytokeratin, vimentin and S-100 protein which is expressed in 90% of CPPs. In around 20% of pediatric cases, these tumors show malignant transformation; approximately half of them are located within the atrium.

They are similar in aspect to the glomus of the choroid plexus, being formed by a single cell layer of cuboid or cylindrical cells surrounded by a thin fibrovascular structure. In the latest World Health Organization (WHO) classification, CPPs are classified as grade I. On NCCT of brain these tumors frequently contain calcifications, hemorrhages in various stages, or cysts. In some cases, CPPs may fill the ventricular cavity, whereas in others, the ventricle may be markedly dilated ipsilaterally.

Surgical excision is currently considered the treatment of choice. The surgical approach should aim to expose and interrupt the proximal arterial supply from the choroidal artery to devascularize the tumor at an early stage of the procedure followed by in-toto excision of the tumor.

In the present case, authors illustrate an unusual presentation of CPP with raised intracranial pressure (ICP) since birth. After the complete surgical excision post-operative period was uneventful and the baby is doing well till last follow-up, 6 months post surgery.

This case illustrates the rare fetal CPP and the need for proper pre-operative planning, meticulous surgical technique, and intensive intra-operative monitoring for normothermia, fluid-electrolyte balance, and blood replacement for achieving excellent results.