Which of the following is NOT listed as a type of primary lung cancer?

Which of the following is NOT listed as a type of primary lung cancer?

• A. Non-small cell lung cancer
• B. Small cell lung cancer
• C. Carcinoid
• D. Mesothelioma

Answer: (D)

The key idea is where the cancer originates. Primary lung cancers start in the lung tissue itself. Non-small cell and small cell lung cancers are the two main types that arise from the lung parenchyma, and carcinoid tumors are also primary lung cancers that come from neuroendocrine cells within the lung. Mesothelioma, on the other hand, starts in the pleural lining that covers the lungs and chest wall, not in the lung tissue itself. It’s a pleural malignancy often linked to asbestos exposure. So it isn’t classified as a primary lung cancer, which is why it’s the correct choice.

The key idea is where the cancer originates. Primary lung cancers start in the lung tissue itself. Non-small cell and small cell lung cancers are the two main types that arise from the lung parenchyma, and carcinoid tumors are also primary lung cancers that come from neuroendocrine cells within the lung. Mesothelioma, on the other hand, starts in the pleural lining that covers the lungs and chest wall, not in the lung tissue itself. It’s a pleural malignancy often linked to asbestos exposure. So it isn’t classified as a primary lung cancer, which is why it’s the correct choice.