In the TNM staging system, what does T0 signify for the primary tumor?

In the TNM staging system, what does T0 signify for the primary tumor?

• A. Tumor extends into surrounding structures.
• B. Tumor invades adjacent organs.
• C. No evidence of primary tumour.
• D. Small primary tumour, limited local invasion.

Answer: (C)

In the TNM system, the T category reflects the presence and local extent of the primary tumor. T0 means there is no evidence of a primary tumor after thorough evaluation. This situation can occur when a patient has metastatic disease but the primary lesion cannot be found or identified. It’s different from a cancer that is in situ (carcinoma in situ), and it does not imply that there is no cancer elsewhere in the body. So the best choice is the one that describes no detectable primary tumor. The other descriptions talk about a tumor that is visible and invading nearby structures or is a small lesion, which would correspond to higher T stages (not T0).

In the TNM system, the T category reflects the presence and local extent of the primary tumor. T0 means there is no evidence of a primary tumor after thorough evaluation. This situation can occur when a patient has metastatic disease but the primary lesion cannot be found or identified. It’s different from a cancer that is in situ (carcinoma in situ), and it does not imply that there is no cancer elsewhere in the body.

So the best choice is the one that describes no detectable primary tumor. The other descriptions talk about a tumor that is visible and invading nearby structures or is a small lesion, which would correspond to higher T stages (not T0).