Footnotes

• Contributors The case for this manuscript was identified by J-WC. Y-JC, W-HW, J-WC were involved in managing the case. K-NL performed simple mastoidectomy for the patient. Photographs and radiographic images were selected and annotated by J-WC. The manuscript was drafted by Y-JC.

• Funding None declared.

• Competing interests None declared.

• Patient consent Parental/guardian consent obtained.

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