Final answer:
The notation used when lymph nodes near a tumor cannot be measured is 'NX', where 'N' indicates the regional lymph nodes and 'X' means they cannot be evaluated. This is part of cancer staging which includes assessments of tumor size (T), lymph node involvement (N), and metastasis (M).
Step-by-step explanation:
When lymph nodes near a tumor cannot be measured directly, the notation used to indicate this is typically 'NX' where 'N' indicates the regional lymph nodes and 'X' signifies that the lymph nodes cannot be evaluated. In cases where cancer is suspected, like in Wei's situation, the lymph nodes can become a focal point of diagnosis. Wei's physician, concerned about the persistent swollen lymph node and other symptoms, requested a biopsy, which is a procedure to remove tissue to determine if there are cancerous cells present. A biopsy might be followed by imaging techniques such as a radioisotope scan, like the one Wei may have had following his diagnosis of lymphoma. This scan uses isotopes attached to antibodies that bind to specific cancer cells, to help locate metastasized tumors. The decision to use 'NX' is part of a larger staging procedure meant to describe the extent of cancer spread, where 'T' describes the size of the original tumor, 'N' describes the involvement of lymph nodes, and 'M' describes the presence of metastasis.