Why are both skin and lung cancer classified as carcinomas?

• A. Because they originate from epithelial cells.
• B. Because they are caused by viral infections.
• C. Because they arise from connective tissue.
• D. Because they only affect internal organs.

Answer: (A)

Verified step by step guidance

1. Understand the definition of carcinoma: Carcinomas are a type of cancer that originates from epithelial cells, which are the cells that line the surfaces of the body, including skin, lungs, and other organs.
2. Identify the tissue type involved in skin and lung cancer: Both skin and lung cancer arise from epithelial cells, which are responsible for forming protective layers and lining internal and external surfaces.
3. Eliminate incorrect options: Review the other choices provided in the question. For example, 'caused by viral infections' is not universally true for all carcinomas, and 'arise from connective tissue' refers to sarcomas, not carcinomas.
4. Clarify the distinction between epithelial cells and other tissue types: Epithelial cells differ from connective tissue cells, which support and connect other tissues, and are not the origin of carcinomas.
5. Conclude why skin and lung cancer are classified as carcinomas: Since both cancers originate from epithelial cells, they are correctly classified as carcinomas, aligning with the definition of this cancer type.