Supratentorial intraventricular solitary schwannoma. Case report and literature review

Objective The objectives of this study were to present a case of a solitary intraventricular schwannoma with a review of the literature and to analyse the current theories of its origin. Description A 16-year-old male patient, without any pathological, genetic or familial history of significance, presented with symptoms of intracranial hypertension and progressive left brachiocrural paresis. The magnetic resonance image showed a bulky intraventricular space-occupying lesion emerging from the posterior horn of the right lateral ventricle, with an irregular nodular component intimately connected to the choroid plexus, and a multiloculated cystic component extending beyond the ventricle. Surgical approach A right parietal craniotomy was performed, revealing a multiloculated cyst with xantochromic fluid and a soft brownish red nodule. The lesion was dissected surrounding the periphery and coagulating a vascular pedicle related to the wall of the right lateral ventricle and its choroid plexus. Total excision was achieved. The pathological exam reported an intraventricular schwannoma (WHO grade 1). The patient evolved favourably, with no recurrence at 36-month follow-up. Conclusion The literature describes less than 45 cases of schwannomas not associated to cranial nerves of the following locations: intramedullary, leptomeningeal and only 12 intraventricular cases. The three theories explaining the origin of this last group describe: (1) a neoplastic transformation of peripheral nerve fibres, (2) a neoplastic transformation of autonomic neural tissue located within the intraventricular choroid plexus and (3) an abnormal embryogenesis leading to a failed migration of the neural crest cells. Complete resection is the therapeutic goal for this benign pathology to avoid recurrence.