Both skin cancer (arising from the epidermis) and most lung cancers are classified as which type of malignant tumor based on tissue of origin?

• A. Carcinoma
• B. Sarcoma
• C. Lymphoma
• D. Glioma

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the classification of malignant tumors based on tissue of origin. Malignant tumors are generally classified into carcinomas, sarcomas, lymphomas, and gliomas depending on the type of tissue from which they arise.
2. Step 2: Recognize that carcinomas originate from epithelial tissue, which includes the epidermis (outer layer of skin) and the lining of organs such as the lungs.
3. Step 3: Identify that sarcomas arise from connective tissues like bone, muscle, or cartilage, which is different from epithelial tissue.
4. Step 4: Know that lymphomas originate from lymphatic tissue, and gliomas arise from glial cells in the nervous system, so these are not related to skin or lung epithelial cancers.
5. Step 5: Conclude that since both skin cancer from the epidermis and most lung cancers arise from epithelial tissue, they are classified as carcinomas.