In the TNM classification, which letter denotes regional lymph node involvement?

In the TNM classification, which letter denotes regional lymph node involvement?

• A. N
• B. M
• C. T
• D. E

Answer: (A)

Regional lymph node involvement is described by the N component. In the TNM system, T stands for the size and extent of the primary tumor, N indicates whether nearby (regional) lymph nodes are involved, and M denotes distant metastasis. Regional lymph nodes are those that drain the area around the tumor; if cancer affects these nearby nodes, that is captured by N. Metastasis to distant organs is M, not regional nodes, and T covers the primary tumor itself. The option E isn’t part of the standard TNM components. So the letter that denotes regional lymph node involvement is the one that corresponds to N.

Regional lymph node involvement is described by the N component. In the TNM system, T stands for the size and extent of the primary tumor, N indicates whether nearby (regional) lymph nodes are involved, and M denotes distant metastasis. Regional lymph nodes are those that drain the area around the tumor; if cancer affects these nearby nodes, that is captured by N. Metastasis to distant organs is M, not regional nodes, and T covers the primary tumor itself. The option E isn’t part of the standard TNM components. So the letter that denotes regional lymph node involvement is the one that corresponds to N.