MSRA-0308

A 70-year-old man is seen on a home visit by his General Practitioner as his wife is concerned about an ulcer on his lower leg, which has been present for a couple of weeks. It is starting to leak clear fluid. He has a history of chronic congestive cardiac failure and chronic obstructive pulmonary disease. A diagnosis of a venous ulcer is suspected.
Which of the following examination findings would best support this diagnosis?