 Most of the time when we're considering masses in the spinal cord, we're in a differential diagnosis between astrocytoma and appendemoma. And frankly, there's a lot written on the distinction, but they often look similarly. So here we have a patient who has a large mass in the cervical spine. And we see that the cord is expanded with diminution in the width of the CSF space at the borders with the mass. And this lesion is dark on T1, bright on T2, as well as bright on the stir image, which is typically what we see also with appendemomas. This case is an astrocytoma. An astrocytoma, as I said, generally tend to be more diffuse in larger regions than appendemoma. When we think about the differential between astrocytoma and appendemoma, we have a few things that we base our criteria on. Number one is that children have a higher rate of astrocytomas than appendemomas, whereas adults favor the appendemoma. Cervical spine lesions, by and large, are more commonly astrocytomas than appendemomas, whereas those in the Rambo-Sacral region, particularly the phylum mixopapillary appendemoma, occur in that location. In addition, we have that hemo-sitterin cap sign that we see with appendemomas, but that would be very rare for astrocytomas. Both of the lesions will enhance generally to a moderate degree. We also saw that with neurofibromatosis type II, the MIS-MI syndrome that has multiple intracranial schwannomas, meningiomas, and spinal appendemomas, you have appendemomas. So neurofibromatosis type II is associated with appendemoma. However, neurofibromatosis type I is associated with cord astrocytomas. So if we have the other findings of NF1, those being the dermatologic café au lait spots, et cetera, axillary freckling, as well as a bony dysplasia indicative of neurofibromatosis type I, we would favor astrocytomas. But this differential diagnosis is accurate at around 70% rate. So this case, where the lesion appears relatively well-defined, although it does have cord edema above and below, we might have suggested appendemoma. However, the fact that this is a child, which we can see by the bone marrow signal-intensity changes, as well as in the cervical region, would argue in favor of astrocytoma. If we pull down the post-catalanine enhanced scan, it's not really going to help us because both lesions will show contrast enhancement to a moderate degree. So this is a cervical spinal cord astrocytoma in a child.