Object returned from FieldInfo.GetValue cannot be cast to Array

I'm working in a PCL (Profile7), and I've got an issue where the object returned from fieldInfo.GetValue(myItem) cannot be cast to an array.

I get a cast exception on a direct cast and (obviously) null when using As

how do I cast this object to a collection?

note: I have no idea what the type is as I don't have access to it. It's internal to the library I'm consuming