Manifestations of pilocytic astrocytoma: a pictorial review

BACKGROUND: Pilocytic astrocytoma can be challenging to diagnose. METHODS: Its clinical presentations can differ, directly related to its size and location, and are relatively unreliable. Similarly, imaging findings also vary with the location of the pilocytic astrocytoma. RESULTS: This review provides an overview of the different imaging findings regarding pilocytic astrocytomas using both conventional and advanced magnetic resonance imaging sequences according to tumour location; the findings are strongly related to the tumour’s tendency to infiltrate surrounding structures, being able to carry out gross total resection, and finally the prognosis. CONCLUSIONS: Knowledge of these imaging manifestations of pilocytic astrocytoma may be helpful to arrive at an accurate diagnosis. TEACHING POINTS: To recognise the various imaging findings of pilocytic astrocytoma on both conventional and advanced magnetic resonance imaging sequences. To identify the characteristic imaging findings according to tumour location. To discuss the relevant differential diagnoses of pilocytic astrocytoma in each tumour location.