Lymph Node Diameter as a Predictor of Lymph Node Metastasis in Patients with Colorectal Neuroendocrine Neoplasms

OBJECTIVES: The ideal cut-off value for the diameter of metastasis-positive lymph nodes (LNs) in patients with colorectal neuroendocrine neoplasms (NENs) is unclear. Thus, in this study, we investigated the correlation between the LN diameter and LN metastasis. METHODS: A total of 148 LNs of 42 patients with colorectal NEN who underwent surgical dissection or local resection from April 2010 to March 2016 were included in the present study. The LN diameters were measured on computed tomography, and LN metastases were either pathologically proven or evaluated during the follow-up period. RESULTS: Overall, 18 (12.2%) LNs were positive for LN metastasis, and 130 (87.8%) were negative. The short diameter in metastatic-positive LNs was longer than that in negative LNs (4.9 [3.0-6.3] vs. 2.0 [1.0-2.0] mm; P = 0.01). An LN of >3 mm predicted LN metastasis with 88.8% sensitivity and 78.5% specificity with an area under the curve of 0.852. CONCLUSIONS: Surgical resection with lymphadenectomy should be considered for patients with LNs of >3 mm in diameter.