This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Surgery
An elderly woman underwent a radical mastectomy with radiation to the axilla 20 years ago. For 25 years, she has had an open wound that has never healed. It is not a recurrence of breast cancer. It is most likely: 
Select and explain. 
A. Basal cell carcinoma, B. Squamous cell carcinoma, C. Hypertrophic granulation tissue, D. Malignant melanoma
B: Squamous cell carcinoma
Answer: B: Squamous cell carcinoma 
Explanation: First described by Marjolin in 1828 and known as Marjolin's ulcers, malignant degeneration arising in a chronic wound is nearly always squamous cell carcinoma. These lesions are most commonly seen in burn scars but have been associated with osteomyelitis, radiation therapy, hidradenitis suppurativa, and diabetic ulcers.