Pilocytic astrocytomas (PA) are benign neoplasms commonly located in the cerebellum
with a peak incidence in the first two decades of life. PA occurrence in adults is
rare and very little information is available in the literature about tumour characteristics
in this population. This study retrospectively identified 20 adults with PA. The characteristics
of the tumour, treatment modalities and patient outcomes are discussed, as well as
identifying factors that may be associated with worse prognosis. The mean age at diagnosis
was 27 years. The majority of PA were located in the posterior fossa. Other tumour
locations included the cerebral hemispheres, brainstem, tectal plate and optochiasmatic
region (optic chiasm, hypothalamus and third ventricle). All patients in this study
underwent surgery, two received adjuvant chemotherapy and one received adjuvant radiotherapy.
Tumour recurrence occurred in six patients and two eventually died from the disease.
When achieved, complete tumour resection was found to be curative. Tumour location
affects extent of surgical resection; tumours in inaccessible locations were associated
with higher rates of recurrence. Overall survival and progression free survival rates
were 87% and 60% respectively. The degree of surgical resection and tumour location
were found to affect prognosis. Unfavourable outcomes were observed in these adults
with PA compared to those expected for a younger population, suggesting a possible
association between age and outcome.