Which skin cancer is characteristically crusted, scaly, and ulcerated and may metastasize?

• A. Basal cell carcinoma
• B. Melanoma
• C. Squamous cell carcinoma
• D. Actinic keratosis

Answer: (C)

Crusted, scaly, ulcerated lesions on sun-exposed skin that may metastasize are characteristic of squamous cell carcinoma. This cancer arises from keratinocytes in the epidermis and tends to be locally invasive with a real risk of spreading to regional lymph nodes or beyond. Basal cell carcinoma usually appears as a pearly, translucent papule with telangiectasias and very rarely metastasizes. Melanoma typically presents as a pigmented lesion with irregular borders and color variation and carries a higher metastatic risk. Actinic keratosis is a rough, scaly patch that is premalignant and can progress to squamous cell carcinoma, but is not itself a malignant, ulcerated lesion.