Schwannoma of the Fourth Ventricle: The Eighth Case Report.
OBJECTIVE
We report an uncommon case of a surgical resection of a fourth ventricle tumor in an adult that proved to be a schwannoma.


METHODS
A 53-year-old man presented with a 1.5-year history of gait unsteadiness and vertigo and a few-week history of headache, emesis, and neurogenic dysphagia. A brain magnetic resonance imaging revealed a large, heterogeneously contrast enhancing mass located within the fourth ventricle, compressing the brainstem and causing supratentorial ventricle enlargement. A suboccipital craniotomy and a telovelar approach were performed to resect the tumor. The ventricular system was repermeabilized at the end of the operation.


RESULTS
A postoperative magnetic resonance imaging confirmed complete tumor removal. There was an initial worsening of the preoperative deficits, which progressively improved. The tumor was classified as a fourth ventricle schwannoma. There has been no evidence of tumor recurrence during the 6 years of follow-up. At present, the patient is ambulatory and reports an intermittent diplopia on conjugated gaze.


CONCLUSIONS
This case report intends to reveal the eighth case of a fourth ventricle schwannoma since 1957. Schwannomas of the fourth ventricle are infrequent but should be accounted in the differential diagnosis of space-occupying lesions in this location. Gross total resection might be the definite treatment of these tumors if deemed possible.
Department of Neurological Surgery, Centro Hospitalar Lisboa Norte, Entidade Pública Empresarial, Lisbon, Portugal. Electronic address: mariamanesantos@gmail.com.
Maria M
MM
Santos
Department of Neurology, Hospital Fernando Fonseca, Amadora, Portugal.
Ângela
Â
Timóteo
Department of Neurological Surgery, Centro Hospitalar Lisboa Norte, Entidade Pública Empresarial, Lisbon, Portugal.
Domingos
D
Coiteiro
Department of Neuropathology, Centro Hospitalar Lisboa Norte, Entidade Pública Empresarial, Lisbon, Portugal.
José
J
Pimentel
D002551:Cerebral Ventricle Neoplasms / Q000473:pathology / Q000601:surgery*; D003399:Craniotomy; D020546:Fourth Ventricle / Q000473:pathology / Q000601:surgery*; D020233:Gait Disorders, Neurologic / Q000209:etiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009442:Neurilemmoma / Q000473:pathology / Q000601:surgery*; D019635:Neurosurgical Procedures; D016896:Treatment Outcome; D014717:Vertigo / Q000209:etiology
Brain tumor; Fourth ventricle tumor; Intra-axial schwannoma