Patterns of lymph node metastasis in patients with resectable esophageal squamous cell carcinoma: Assessment by multi-slice computed tomography

Objective: To investigated the multi-slice CT (MSCT) features and distributions of thoracic-abdominal lymph node metastasis at different T stages in patients with thoracic esophageal squamous cell carcinoma (ESCC). Material: and methods A total 329 surgical proven ESCC patients associated with lymph node (LN) metastasis from Affiliated hospital of North Sichuan Medical College were enrolled, and the clinical and medical image data of all patients were retrospectively reviewed. 104 of the 329 patients were women and 225 were men (age range 38-82 years and mean age 55.8 ± 9.2 years). These patients were divided into pT₁ group (tumor limited within the submucosal layer) and pT_2-3 group (tumor invading or penetrating the muscle layer). The metastatic LNs were evaluated by MSCT, the features including size, attenuation and enhancement pattern, and were compared with pathologic results with Kappa coefficient. The distributions of involved lymph nodes in patients with different T stage were also recorded. Results Fifty one of the 329 patients were staged as PT₁ (51/329, 15.5%) while 278 were staged as p T_2-3 (278/329, 84.4%). A total of 967 metastatic LNs were observed on MSCT. In patients with thoracic ESCC, the diagnosis of lymph node metastasis on MSCT had relative good accordance with pathologic result (κ = 0.708), and the LNs in upper mediastinum and peri gastric area were more frequently involved. In patients with tumor limited within the submucosal layer (pT₁) and located in upper esophagus, LNs were more frequently involved in the upper mediastinum, whereas tumor located in the mid and lower esophagus, LNs were more frequently involved in the peri-gastric area than in the mid-or lower mediastinum. In patients with tumor invading or penetrating the muscle layer(pT_2-3), LNs were more involved in the upper mediastinum and peri-gastric area, and node metastasis in the mid-and lower mediastinum increased dramatically compared with p T₁ group (all P < 0.05). Conclusion: The LN metastasis in thoracic ESCC could be detected with high accuracy by using MSCT, and the distribution of metastatic LNs varies according to T stage in patients with ESCC. (authors)