Lymph Node Metastasis in Colorectal Cancer.

Pathologic examination of lymph nodes in patients with cancer remains crucial for postoperative treatment and prognosis prediction. In this article, the authors aim to review several important and challenging issues regarding lymph node metastasis in colorectal cancer using the AJCC staging manual, College of American Pathologists cancer protocol, as well as the literature. These topics include lymph node staging, the definition and controversies in tumor deposits, isolated tumor cells in lymph node and micrometastasis, lymph node ratio as a prognostic stratification factor, and neoadjuvant treatment effect in rectal cancer. Updates from the most recent AJCC 8th edition are included.