"T2*/GRE/SWI: signal loss if calcification or haemorrhage present"
"MR spectroscopy: high choline and lactate peak 13"
"MR perfusion: low to moderate rCBV 17"
"Pilocytic astrocytomas vary significantly in morphology ranging from tumours dominated by a large cyst with a smaller mural nodule, to mostly solid tumours, and particularly in adults, heterogenous masses with haemorrhage, necrosis and calcification."
"GFAP: positive"
"atypical teratoid/rhabdoid tumour (AT/RT)"
"atypical teratoid/rhabdoid tumour (AT/RT)"
"Pilocytic astrocytoma almost invariably have alterations in the MAPK pathway. In patients with neurofibromatosis type 1, the mutations are in the NF1 gene. Otherwise, BRAF alterations are most common, (present in ~70% of cases). Other relatively common mutations include FGFR1 mutations or fusion and KRAS mutations 6. Importantly they, along with other paediatric low-grade gliomas, lack IDH mutations and TP53 mutations 6,7."
"low ADC values has been reported in BRAF V600E tumours 13"
"solid component: iso- to hypointense compared to adjacent brain"
"For tumours with a cyst and mural nodule, some surgeons advocate that only the nodule needs to be resected to achieve a cure, as the cyst walls are non-neoplastic, even if enhancing 2,6. Other studies suggest that the likelihood of tumour being present in the cyst wall is much higher if enhancement is present and is often obvious intra-operatively 9.Incompletely resected tumours, unresectable tumours, or those that recur may be treated with radiotherapy, with over 70% 10-year progression-free survival in children 18."
Expected headings
"Grading"
"There is a strong association with NF1. NF1-associated tumours have a tendency to affect the optic nerves and chiasm (see: optic pathway glioma). The association between NF1 and pilocytic astrocytomas is so strong that up to 20% of all patients with NF1 will develop these tumours, typically in early childhood. Conversely, approximately one-third of pilocytic astrocytomas involving the optic nerves have associated NF1."
"Pilocytic astrocytomas vary significantly in morphology ranging from tumours dominated by a large cyst with a smaller mural nodule, to mostly solid tumours, and particularly in adults, heterogenous masses with haemorrhage, necrosis and calcification."
"In children, (in the posterior fossa) these tumours are typically slow-growing and well-circumscribed and as such surgical resection is the treatment of choice. If complete, it is usually curative (overall good prognosis in children following treatment; 10-year survival >95%) 6."
"History and etymology"