Where is squamous cell carcinoma most commonly located?

• A. Lips, hands, neck, and head.
• B. Back and abdomen.
• C. Sole of foot.
• D. Palms only.

Answer: (A)

Squamous cell carcinoma tends to develop in skin or mucous membranes that have been exposed to a lot of sun. Chronic UV damage drives mutations in squamous cells, so the most common sites are sun-exposed areas of the head and neck, including the lips, ears, face, and the dorsum of the hands. Among the options, the set that reflects these sun-exposed regions—lips, hands, neck, and head—fits the usual pattern of where SCC occurs most often. The other sites describe areas that are less commonly affected by primary cutaneous SCC (such as the sole of the foot or palms alone, or areas not typically exposed like the back and abdomen).