Table 2.

Proposed clinical warning signals for high-risk chronic wounds suspicious for Marjolin ulcer.

Domain	Warning signal	Clinical significance
Time	Wound that fails to heal or recurs within 2–3 months despite appropriate care	Short-term non-healing suggests an underlying pathological process distinct from common benign wounds and warrants further investigation.
	Chronic wound persisting for decades (e.g., >10 years)	Extended duration provides a prolonged window for cumulative malignant transformation within the chronic inflammatory microenvironment.
Morphology	Cauliflower-like, stone-hard, or ulcerative growth with elevated, firm, and easily bleeding margins	These macroscopic features are classic signs of malignant transformation in chronic wounds and should trigger immediate suspicion.
	Persistent exudation, erythema, swelling, and pain, with preserved blood supply but local sensory loss	The discordance between good perfusion and sensory deficit suggests deep infiltration involving peripheral nerves, a feature of advanced disease.
Context	Elderly male patient	Consistent with the known demographic profile of Marjolin ulcer (male predominance, peak incidence in the 5th–6th decades of life).
	Lesion arising on a background of old trauma, burn scar, or long-standing non-healing ulcer.	Any chronic wound environment, regardless of the initial insult, can serve as a carcinogenic niche and should be evaluated with heightened vigilance.

Summary of practical clinical warning signals derived from the present case series and literature review. These signals are not intended as diagnostic criteria but rather as a practical aid to raise clinical suspicion and prompt timely biopsy or specialist referral.