Primary pilocytic astrocytoma of the cerebellopontine angle in pediatric patient with neurofibromatosis type 1: a case report

Abstract

Background: Cerebellopontine angle tumor (CPA) in pediatrics is rare as compared to adults. We describe a case of pediatric pilocytic astrocytoma presented as a right CPA mass with a concurrent clinical diagnosis of neurofibromatosis type 1 (NF1).

Case presentation: A 14-year-old boy with a newly diagnosed hypertension presented with a short history of headache and blurring vision. Neurological examination revealed bilateral papilloedema, partial right third nerve palsy and mild sensorineuronal hearing deficits. Skin examination identified multiple café au lait spots with cutaneous neurofibromas. Preoperative neuroimaging suggested the diagnosis of an extraaxial CPA mass consistent with meningioma, with obstructive hydrocephalus. A left ventriculoperitoneal shunt was inserted and the child was subjected for a suboccipital retrosigmoid approach for tumor resection. The histopathological features, however, were typical for pilocytic astrocytoma.

Conclusions: A careful evaluation of the clinical presentation and radiological images of CPA lesions is necessary prior to surgical embarkment. To the best of our knowledge, this case is the first report of pilocytic astrocytoma in the CPA in pediatric with NF1.

Keywords: Cerebellopontine angle; Neurofibromas; Neurofibromatosis; Pilocytic astrocytoma; Schwannoma.

Fig. 1

Radiological images. A An axial CT brain revealing a right hypodense CPA tumor (asterisk) that enhances following B contrast sequences, with C IAC enlargement. T2-weighted MR image demonstrating heterogeneous intensity lesions on D axial and E coronal sequence. F, G On the T1-weighted post gadolinium, a heterogenous enhancement is seen following gadolinium. H Day 1 postoperative axial CT brain showing resection cavity with partial relief of brain stem compression

Fig. 2

Hematoxylin–eosin stain. The tumor shows a biphasic appearance with A compact fibrillar area, and B loose microcystic area (× 10 magnification). C Rosenthal fibers (orange arrow) and eosinophilic granular bodies (red arrow) are present (× 20 magnification). D Immunohistochemical expression of positive glial fibrillary acidic protein (× 10 magnification)