What is the most unusual disease u have come across

Question: What is the most unusual disease u have come across
- Keywords:
  disease,
  rare
Asked by Hfrbyvrtvhtbhbe to Kevin, Liz, Beccy, Rosie on 14 Jun 2017.
- anon answered on 14 Jun 2017:
  
  lung worms – I find that the most awful to contemplate of the parasitic diseases I know
- Rebecca Corkill answered on 14 Jun 2017:
  
  Loa loa worm. This is known as the eye worm, as it normally localises in that organ.
- Rosie Fok answered on 14 Jun 2017:
  
  It is not an infection, but a type of tumour called a teratoma. The tumour can grow recognisable bits of body tissue, in the wrong place. So, you can find a perfectly formed molar tooth, for example, in someones abdomen.

Question: What is the most unusual disease u have come across