Background
Radiation ulcer is a severe form of radiation dermatitis, consequent to skin injury from exceeding cumulative radiation dose. Radiation ulcer, thought to be rare, is on the rising due to broad application of percutaneous coronary interventions (PCI).

Case presentation
A 81-year-old male with history of hypertension and triple vessel coronary artery disease underwent percutaneous coronary interventions. The patient complained of right arm skin erosions 6 months after PCI. It did not resolve with conservative treatment and developed into refractory skin ulcer. Radical excision and immediate reconstruction with latissimus dorsi myocutaneous flap were subsequently performed.

Result
The pathology of the excised tissue showed epidermal ulceration, dermal fibrosis and fatty necrosis, consistent with radiation dermatitis. The wound healed well and the patient was able to raise his right arm. No recurrence was identified with 10-year follow-up.

Conclusion
Diagnosis of radiation ulcers is challenging and requires thoughtful history taking and physical examination. Although radical excision with flap reconstruction is an effective remedy, measures to prevent its development shall be taken into consideration in radiation- associated treatment procedures.