d) Squamous cell carcinoma is the most common type
d. squamous cell carcinoma
When a SCC or BCC occurs in a long standing scar, it is called marjolin's ulcer.
Marjolin's type of ulcer is a malignant change that can occur in any long standing ulcer (ie venous ulcer)
Scar tissue is devoid of lymphatics, so no lymphatic spread. Lymphatic spread can still occur when it invades normal tissue. also nerve endings are not in scar tissue, so pain is a late feature
They are slow growing tumors but have propensity for distal metastasis and squamous cell carcinoma is the most common type. Slow growth is again due to avascular characteristic