Morphometric analysis of regional lymph nodes with and without metastasis from early gastric carcinoma

To the authors' knowledge detailed morphometric changes in lymph nodes with and without metastasis in patients with early gastric carcinoma remain undocumented.

Histologic slides of 1847 lymph nodes dissected from 115 consecutive patients who underwent gastrectomy for early gastric carcinoma were examined histologically and measured using computer morphometry with the public domain National Institutes of Health Image program. Quantitative data were analyzed in relation to preoperative and intraoperative clinical assessments and postoperative pathologic diagnosis.

Metastasis was found in 11 lymph nodes (0.6%) from 8 patients (7.0%). Metastatic lymph nodes showed a mean maximum dimension of 4.8 mm, a mean area of 14.4 mm(2), and a mean ratio of maximum/minimum dimension of 1.36; the corresponding values for nonmetastatic lymph nodes were 4.7 mm (P = 0.45), 13.2 mm(2) (P = 0. 13), and 1.66 (P = 0.10), respectively. The lymph node with a metastasis was not necessarily the largest of the dissected lymph nodes from each patient, and histologically each lymph node with a metastasis showed pericancerous fibrosis in > 10% of its area. The sensitivities of preoperative computed tomography, abdominal ultrasonography (US), endoscopic US, and intraoperative assessments to diagnose metastasis were 0%, 13%, 0%, and 13%, respectively, and the sensitivities of these modalities to detect lymph nodes > 10 mm in dimension were 18%, 10%, 3%, and 10%, respectively.

Digital quantitative analysis is useful and widely applicable to clinicopathologic evaluation. The diagnostic sensitivity of lymph node metastasis in patients with early gastric carcinoma in the current study was very low with preoperative and intraoperative assessments because lymph node metastases were small and showed subtle histologic changes of pericancerous fibrosis.