Haemangioblastomas of the posterior cranial fossa

Haemangioblastoma: a rare cause of a cerebellar mass in the elderly

In the elderly, cerebellar lesions are commonly metastatic tumours with poor prognosis. We describe two octogenarians who presented with obstructive hydrocephalus, secondary to posterior fossa tumours that, on computed tomography, were thought to be cerebellar metastases. Both lesions were excised and the histology proved them to be cerebellar haemangioblastomas, primary benign tumours of the posterior fossa, which are rare in the elderly.

Postpartum cerebellar herniation in von Hippel-Lindau syndrome

PURPOSE

To describe exacerbation during pregnancy of cerebellar hemangioblastoma in von Hippel-Lindau syndrome.

METHOD

Case-report. A 21-year-old woman with von Hippel-Lindau syndrome was found on routine ocular examination to have severe papilledema 1 week after giving birth.

RESULTS

Immediate magnetic resonance imaging disclosed a large cerebellar cyst from hemangioblastoma causing cerebellar tonsillar herniation. Immediate neurosurgical intervention was life saving.

CONCLUSION

Worsening of intracranial hemangioblastoma during pregnancy in cases of von Hippel-Lindau syndrome should be realized and periodic neurologic and ophthalmologic observation is warranted.

Surgical management of haemangioblastoma of the posterior fossa

Fifty-one cases of posterior fossa haemangioblastoma have been seen in our department over a period of 23 years. Seven cases were associated with spinal cord lesions and one with a supratentorial lesion. There were 22 cases of Lindau's disease (43%). The onset was earlier and recurrences commoner than in isolated cases. In 10 cases the development of new tumours in different parts of the central nervous system (CNS) required re-operation, demonstrating the multicentric nature of this disease. The majority of the tumours occupying the fourth ventricle or medulla oblongata (8 cases) were macroscopically solid and had higher post-operative morbidity than the cystic tumours in the cerebellum. The recent development of magnetic resonance imaging (MRI) provides accurate anatomical information of the lesions (especially those of the brain stem and spinal cord) even while asymptomatic. The brilliant enhancement of these tumours on MRI with Gadolinium-diethyline-triamine-pentaacetic acid (Gd-DTPA) has proved to be particularly useful.

The role of image-directed biopsy in the diagnosis and management of brainstem lesions

The appreciation that brainstem tumours do not comprise a homogeneous pathological group and that up to 20% of the preoperative radiological diagnoses of brainstem lesions prove at operation to be wrong, has established the need for a firm histological diagnosis prior to treatment. Current neuro-imaging modalities may have increased the diagnostic accuracy and the detection rate of intrinsic brainstem lesions, but open exploration in cases without an exophytic component is still associated with a low diagnostic yield and considerable morbidity. A series of 72 brainstem lesions approached stereotactically with CT or MRI guidance is presented. A transcortical frontal precoronal trajectory was used in 58 and a suboccipital transcerebellar route in 14. Haematoma was diagnosed preoperatively in 16 cases and therapeutic aspiration was planned. In 56 cases the diagnosis was uncertain, although intrinsic tumour was suspected. A histological diagnosis was established in 52 cases, although in the remaining four cases a tumour was excluded. Unexpected findings occurred in over 15% of the cases. There were no operative deaths and the morbidity was low. In no case was there a permanent neurological deterioration directly related to the procedure, although there was a transient deterioration in two patients and another patient required early re-aspiration of a haematoma.

Image directed stereotactic surgery for brain stem lesions

Advances in neurological imaging may have increased the diagnostic accuracy and the detection rate of intrinsic brain stem lesions, but a histological diagnosis is still an essential requirement for rational and appropriate management. Open exploration allows biopsy and resection in cases where an exophytic component is present. The surgical inaccessibility and the resultant morbidity of these approaches, however, associated with a low diagnostic yield in cases with no visible surface abnormality, are important limiting factors. A series of 45 brain stem lesions stereotactically approached with CT or MRI guidance is presented. A transcortical frontal pre-coronal trajectory was used in all of them. Haematoma was preoperatively diagnosed in 10 cases and the procedure was for therapeutic aspiration. Of 35 cases where the diagnosis was uncertain, although intrinsic tumour was suspected, positive results were obtained in 33, while unexpected findings of granuloma, lymphoma, angioma, leucoencephalopathy, vasculitis and radiation necrosis were found in over 10% of the cases. There were no operative deaths and the morbidity was low. In no case was there a permanent neurological deterioration directly related to the procedure, although there was a transient deterioration in two patients and one patient required early reaspiration of a haematoma. Image directed stereotactic approaches to brain stem lesions can combine a high degree of accuracy (offering positive histological diagnoses) with a low operative morbidity. MRI directed biopsies can complement CT guided ones thus increasing the number of suitable cases and improving the success rate. The frontal precoronal transcortical trajectory provides safe access to the majority of the brain stem targets.