Apart from being a tongue twister :)
I didn't recognise the name at first but instantly recognised the disorder once I checked up on it.
This condition arises when an individual doesn't recognise a part of their body as being their own or when a limb feels as if it shouldn't be there. This creates an intense desire to rid oneself of the offending limb. Here there is an incredibly difficult decision to be made on the part of healthcare practitioners.
There are a few hypotheses for this condition but one promising theory involves the parietal lobe. There is an interesting paper co-authored by an incredible neuroscientist V.S Ramachandran whose work in phantom limbs has been absolutely revolutionary - I would wholeheartedly recommend his book 'Phantoms in the brain'.
Anyhow this paper suggests and provides evidence in support of the claim that this condition arises as the result of superior parietal regions which are responsible for somatosensory input and regulation. Basically this area is responsible for providing a reliable sense of body image.
The paper 'Apotemnophilia: a neurological disorder' can be found here (Also features a couple of case studies for added interest) :
@Daniel Sumner thanks for this answer!
@Daniel Sumner thanks for providing clarity