Footnotes

• Handling editor Josef S Smolen

• Contributors SC: clinician, consenting of patient, writing up of case. GM: clinician, editing case write up, liaising with radiology for best images. PD: radiology images and description.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests None declared.

• Provenance and peer review Not commissioned; externally peer reviewed.