Colon cancer: pathology report says pt4a pn1c. and it also says no lymph nodes involved, how could that be?

IIIB disease: T stands for tumor and n stands for nodular ( lymph node). N1- means there is involvement of cancer to 1-3 regional lymph node(s) . If there is no lymph node involvement-but there are nodules in the extra-tumoral soft tissue, away from the primary tumor-is called pn1c. The stage will be the same as t4an1a or b- stage iiib.

Terminology: These are difficult to interpret. The score p means pathologic stage. The pt4a means the cancer grew through all colon layers and the external colon layer but not attached to other organs. The pn1c means no lymph nodes involved but separate nodules of tumor were located away from the primary cancer site.

Answer Clarification: Although no express lymph nodes were involved by carcinoma on path, there were tumor deposits in the mesocolon (fat). It cannot be proven whether any of these were lymph nodes overwhelmed by tumor or ostensibly lymphatics harboring tumor cells in transit to lymph nodes. It is, however, distinctly separate from the main lesion which is pathologically staged based on depth of invasion.

Not in lymph nodes: In general, the 'N' of a tumor staging report refers to involvement of lymph nodes, and anything that isn't 'N-0 (zero)' usually means there are lymph nodes involved by tumor. However, 'N' staging is different for every organ site . In the colon, the N1c stage specifically refers to there being tumor deposits in the fat outside of the colon wall, but not in the lymph nodes themselves.