Footnotes

• Contributors BS was involved in collecting data and writing the manuscript. MN was involved in writing the manuscript and drafting the article. MR was involved in reporting and interpretation the images. OS and AO'M were involved in diagnosis and management of the case; AO'M was also involved in drafting and writing the manuscript. DC was involved in diagnosis and management of the case. He was also involved in revising the article critically for important intellectual content and final approval of the version to be published.

• Competing interests None.

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