Footnotes

• Contributors Each author has contributed sufficiently. RB and AC managed the case and made the diagnosis, clinically. RB submitted the manuscript. RB and AC wrote the manuscript. RB, AC and DK managed the case. PD made the histopathological diagnosis and provided photomicrographs.

• 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.

• Patient consent for publication Obtained.

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