Primary choroid plexus papilloma of cerebellopontine angle: An unusual entity in infancy.

Dear Sir,

Choroid plexus tumors constitute up to 0.4% of all intracranial tumors.[1] These involve lateral ventricles in infancy and childhood and fourth ventricle in adults. Other uncommon locations include third ventricle, intraparenchymal, and cerebellopontine angle (CPA).[123] The primary location of choroid plexus papilloma (CPP) in CPA in infancy has not been perhaps reported yet in literature. We present such a case and discuss the surgical challenges involved.

A 9-month-old male infant was brought with complaints of frequent vomiting, poor feeding, and enlarging head size for 1 month. On examination, the child had spontaneous eye opening and spontaneous movements. He had a bulging anterior fontanelle and papilledema. Contrast-enhanced computed tomography head revealed gross hydrocephalus with a contrast-enhancing lesion in the right CPA. Magnetic resonance imaging (MRI) demonstrated an extra-axial lesion in the right CPA that was hypointense on T1-weighted images (T1-WIs), hyperintense on T2-WI, and showed dense enhancement on gadolinium [Figure 1a–c]. In view of hydrocephalus, the child was taken up for emergency ventriculoperitoneal shunt. The symptoms of raised intracranial pressure subsided and the child was discharged. Definite surgery for tumor excision was deferred until the patient's general condition improved. Over the next 2 months, vomiting stopped, child's feeding improved, he gained weight, and hemoglobin improved, and at this stage, he was taken up for definitive surgery. The right retrosigmoid approach was taken. Intraoperatively, an extra-axial vascular lesion was seen which was soft in consistency, multilobulated with a frond-like appearance. The surrounding cranial nerves were displaced. Complete excision was achieved and postoperative course was uneventful. The histopathology was suggestive of CPP. The child got discharged after 4 days and is symptom-free at 4 months. Repeat imaging shows no residual tumor [Figure 1d–f].

Figure 1

(a) Axial T1-weighted images magnetic resonance imaging showing hydrocephalus tumor in cerebellopontine angle region. (b) Axial contrast-enhanced magnetic resonance imaging showing an intensely contrast-enhancing tumor in the right. (c) Contrast-enhanced sagittal magnetic resonance imaging showing the tumor causing obstruction to cerebrospinal fluid outflow near obex. (d-f) Postoperative images. (d) Axial noncontrast-enhanced computed tomography and (e) axial contrast magnetic resonance imaging and (f) sagittal contrast magnetic resonance imaging showing complete tumor excision

CPPs are rare congenital tumors of neuroectodermal origin that affect both in childhood and adult age. CPA involvement in CPP is known in 9–16% of cases.[123] While 10% of all CPPs are reported to affect in infancy, a primary CPA CPP presenting in infancy is still unheard of.[2]

Such large tumors in infancy pose a unique set of surgical challenges, both due to a relatively difficult location and overall low blood volume in this age. Contrast-enhanced MRI is the investigation of choice. These lesions appear as multilobulated extra-axial vascular masses with a cauliflower-like appearance.[145] Differential diagnoses at this location include - acoustic schwannoma, trigeminal neuroma, ependymoma, and meningioma. While intrameatal extension is the hallmark in acoustic schwannoma, the broad dural attachment in meningioma, extension to the foramen of Luschka in ependymoma, and T1-W hyperintensity in trigeminal neuroma provide diagnostic aid for differentiation.[1]

Due to poor feeding and cachectic state of the patient, we proceeded for ventriculoperitoneal shunt only initially. Definitive surgery for tumor excision was postponed until the general condition improved. The extreme vascular state demanded coagulation of tumor surface under continuous irrigation. Complete excision is the goal, and the same becomes a formidable task in infants. Being a benign tumor, the role of radiotherapy is limited to large residual tumors or when histological features are suggestive of malignant changes.[5]

To conclude, a case of CPP located in CPA in an infant has been described. As far as our search of literature goes, this has not been described previously. There are peculiar surgical challenges in operating on highly vascular lesions at such a small age and difficult location. The trick probably lies in adequate preoperative optimization.

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