Background and Objectives: It is important to identify the initial lymph node metastasis when performing less invasive surgery. The purpose of the present study was to analyze locations of solitary lymph node metastasis and micrometastasis in esophageal carcinoma. Methods: We retrospectively analyzed the initial sites of lymph node metastasis in esophageal cancer. Sixty-five consecutive patients with solitary lymph node metastasis, and 33 pN0 patients with only lymph node micrometastasis detected by immunohistochemistry, were classified according to tumor location and tumor depth.
Results: The location of lymph node metastasis in the 22 patients with superficial cancer was limited to recurrent nerve nodes (RN) in the upper thoracic esophagus; RN, paraesophageal nodes (PE), or perigastric nodes (PG) in the middle or lower thoracic esophagus. Thirty-six patients with advanced cancer had lymph node metastasis at RN, PE, or PG locations, while in the remaining seven, lymph node metastasis was found in areas far from the primary tumor. Regarding the 33 patients with lymph node micrometastasis, the locations of micrometastasis were similar to those of solitary metastasis. Conclusions: Although less invasive surgery, such as reduction of lymphadenectomy, may be suitable for superficial cancer, it should be performed with special care in advanced cancer.