Footnotes

• Contributors KHF prepared the clinical write up and discussion. RR envisioned the study, coordinated the work and edited the manuscript. DPC, CY Lam and MC performed the laboratory work. CY Lui and NL were responsible for clinical care for the patient and manuscript writing. AWHC reviewed the histopathology and helped with manuscript writing. SSL envisioned the study, oversaw the laboratory work and manuscript writing.

• Competing interests None declared.

• Patient consent Obtained.

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