Marjolin's ulcer is:-

Marjolin's Ulcer Low grade SCC, which develops on a chronic benign ulcer or a long standing scar tissue. Arises from the edge of the ulcer Marjolin's ulcer may develop in Post burn scar Long standing venous ulcer Chronic ulcer due to trauma Chronically discharging osteomyelitis sinus Post - radiation ulcer Characteristic Features Slow growing as scar tissue is relatively avascular No secondary deposits in regional lymph node, as there are no lymphatic vessels in scar tissue If the ulcer invades the normal tissue, then only lymph node may be involved by lymphatic spread Radioresistant due to avascularity