Transformation of juvenile pilocytic astrocytoma to anaplastic pilocytic astrocytoma in patients with neurofibromatosis type I.
ABSTRACT Patients with juvenile pilocytic astrocytoma (JPA) and neurofibromatosis type I (NF-1) tend to have a more indolent course than those with sporadic tumors. In rare circumstances, transformation to anaplastic pilocytic astrocytoma (APA) has been known to occur in sporadic cases and is associated with exposure to ionizing radiation. We present 2 patients with NF-1 who were initially diagnosed with JPA that later transformed to APA. Both patients were not exposed to ionizing radiation but instead received alkylator chemotherapy before transformation. Possibility of conversion to APA should be considered in patients with NF-1 and JPA who have rapid tumor recurrence.
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ABSTRACT: Background:High-grade glioma (HGG) of the cerebellum accounts for only 5% of paediatric HGG. Since little is known about these tumours, the present study aimed at their further characterisation.Methods:Twenty-nine paediatric patients with centrally reviewed cerebellar HGG were identified from the HIT-GBM/HIT-HGG database. Clinical and epidemiological data were compared with those of 180 paediatric patients with cortical HGG.Results:Patients with cerebellar tumours were younger (median age of 7.6 vs 11.7 years, P=0.028), but both groups did not differ significantly with regard to gender, tumour predisposing syndromes, secondary HGG, primary metastasis, tumour grading, extent of tumour resection, chemotherapy regimen, or radiotherapy. Except for an increased incidence of anaplastic pilocytic astrocytoma (APA) in the cerebellar subset (20.7% vs 3.3%; P<0.001), histological entities were similarly distributed in both groups. As expected, tumour grading had a prognostic relevance on survival. Compared with cortical HGG, overall survival in the cerebellar location was significantly worse (median overall survival: 0.92±0.02 vs 2.03±0.32 years; P=0.0064), and tumour location in the cerebellum had an independent poor prognostic significance as shown by Cox-regression analysis (P=0.019).Conclusion:High-grade glioma represents a group of tumours with an obviously site-specific heterogeneity associated with a worse survival in cerebellar location.British Journal of Cancer advance online publication, 18 July 2013; doi:10.1038/bjc.2013.404 www.bjcancer.com.British Journal of Cancer 07/2013; · 5.08 Impact Factor