Upload memory stream with form data

I am looking for a way to upload a file to a memory stream along with additional form data, without saving the file to the local file system.

I have looked at the MultipartMemoryStreamProvider and the MultipartFormDataStreamProvider, but cannot see how to access form data with the MultipartMemoryStreamProvider whilst the MultipartFormDataStreamProvider gives me access to the form data but seems to save file data locally, from which I guess I'd need to read the file into a memory stream for me to then use it, which seems a bit of an overhead, unless I am missing something?

Thanks

Anthony