A 72-year-old man who is a retired construction worker comes to the physician because he has had a lesion on his face for 3 months. Physical
examination shows a 6-mm, red, ulcerated lesion with heaped borders. A biopsy specimen of the lesion shows atypical, dysplastic keratinocytes
within the epidermis and dermis. Which of the following is the most likely diagnosis?
(A) Actinic keratosis
(B) Discoid lupus erythematosus
(D) Mycosis fungoides
(E) Squamous cell carcinoma
Correct answer : (E) Squamous cell carcinoma
Explanation: History of sun exposure (UV light), morphology and histology are characteristic of squamous cell carcinoma.