Given the known history of neurofibromatosis type 1, what is the most likely diagnosis?
Both spinal astrocytomas and spinal pilocytic astrocytomas are recognised in patients with NF1 and they can appear very similar.
Intramedullary expansile eccentric and predominantly right sided solid/cystic mass present which demonstrates heterogenous enhancement and measures 10 x 9 x 42 mm (AP x RL x CC) and is centred on the T10 vertebral body and extends from the T9 to the T11 superior endplate (counting from above, from C1). T2 hyperintensity demonstrated within the cord superior to the mass. Some low T2 signal within but no discrete haemosiderin cap.Bone marrow signal is normal. Alignment is normal.