Manifestations of pilocytic astrocytoma: a pictorial review

Abstract

BackgroundPilocytic astrocytoma can be challenging to diagnose.MethodsIts 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.ResultsThis 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.ConclusionsKnowledge of these imaging manifestations of pilocytic astrocytoma may be helpful to arrive at an accurate diagnosis.Teaching PointsTo 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.

Heterogeneity of histopathological presentation of pilocytic astrocytoma – diagnostic pitfalls. A review

“…The neuroimaging findings of PAs, including conventional and advanced magnetic resonance imaging (MRI) sequences, depend on the tumour size, location and tendency to infiltrate the surrounding structures [22]. Typically, PA occurs on computed tomography (CT) and MRI as a well-demarcated, contrast-enhancing lesion that reveals characteristic solid and micro-or macrocystic components [98].…”

Suprasellar pilocytic astrocytoma in an adult with hemorrhage and leptomeningeal dissemination: case report and review of literature

“…PMA is considered as a variant of PA, most often found in the hypothalamus or optic pathways [3], [6]. PMA is more aggressive than the classic PA and classified as WHO grade II [1].…”

“…It is associated with an excellent prognosis with 10 years survival rate reaching 95% after complete resection [4], [5]. Imaging of PA often reveals a cystic lesion with an intensely enhanced mural nodule occasionally accompanied by enhancement of the wall of the cyst [6]. Less common, PA appears as a solid lesion, either homogenous or heterogeneous, particularly when localized in the hypothalamic region.…”

“…Less common, PA appears as a solid lesion, either homogenous or heterogeneous, particularly when localized in the hypothalamic region. Intratumoral hemorrhage and leptomeningeal dissemination (LD) are atypical features of PA [6], [7]. Intratumoral hemorrhage in PA is very rare with only 32 cases being reported from 1977 to 2008 [8], [2].…”

Adult cervicomedullary pilocytic astrocytoma: A case report

“…In general, the cystic part of PA lesions displays hypointensity on T1-weighted images and hyperintensity in T2-weighted MRI images. In the solid part of PA, MRI scans reveal a T1-weighted isointense or slightly hypointense signal, with or without contrast enhancement; by contrast, on T2-weighted scans, the lesions exhibit slight hyperintensity or mixed signals (9). Absence of peritumoral edema is one of the characteristics of PA.…”