Final answer:
Squamous cell carcinoma is a type of cancer affecting the squamous cells of the epidermis and can manifest as lesions commonly found on the scalp, ears, and hands. It is more aggressive and can metastasize compared to basal cell carcinoma. Surgery and radiation are common treatment options.
Step-by-step explanation:
Squamous Cell Carcinoma
Squamous cell carcinoma is a type of cancer that originates in the squamous cells, which are flat, keratin-filled cells located in the upper layers of the epidermis. As for its occurrence in the esophagus, it typically arises in the middle and lower portions. Squamous cell carcinoma of the skin is the second most common type of skin cancer, often presenting as lesions on the scalp, ears, hands, and sometimes on the nose, as indicated in Figure 5.19. Unlike basal cell carcinoma, which rarely metastasizes and is the most common skin cancer, squamous cell carcinoma is more aggressive and can spread if not removed early. The American Cancer Society reports that approximately two out of 10 skin cancers are squamous cell carcinomas. Surgical removal and radiation are primary treatment options for this form of cancer, which are usually effective if the condition is diagnosed early.