Pattern of lymph node metastases of squamous cell esophageal cancer based on the anatomical lymphatic drainage system: efficacy of lymph node dissection according to tumor location

Abstract

Knowing the anatomical lymphatic drainage of the esophagus is crucial to understanding the dissemination pattern of esophageal tumor. During the embryonal growth, the middle and lower part of the esophagus stretches as the lymphatic networks develop in the submucosal layer. The abundant submucosal lymphatics drain in a longitudinal fashion directly to their proximal and distal ends. The lymphatic route from the proximal esophagus through recurrent nerve nodes to supraclavicular nodes are a component of the mesentery of the proximal esophagus. The lower esophagus mostly drains its lymph into paracardial nodes related to celiac nodes through the mesentery of the distal esophagus. Lymphatic routes to mid and lower paraesophageal nodes usually originate from the intermuscular area of the muscularis propria. The lymphatic communication between the submucosa and intermuscular area is limited. The anatomical concept was confirmed clinically by a large series of single institution and the nationwide registry in Japan. The clinical data for the incidence of involved nodes verified the anatomical observations that long longitudinal extension of lymphatic drainage in the submucosa connected to the upper mediastinum lymphatics and paracardial lymphatics. The extent of dissection should be not tailored according to the anatomical distance from the tumor but according to the incidences of metastasis of each area, those were differed by tumor location. The areas for node dissection should be modified according to the tumor location. Although in patients with tumor limited to within the submucosal layer, even with tumors located in the mid-and lower esophagus, lymphatic metastasis was frequent in the upper mediastinum and perigastric area via the abundant submucosal lymphatics in a longitudinal fashion. When tumor invades or penetrates the muscle layer, the incidence of paraesophageal lymph node metastasis in the middle and lower mediastinum increases.

The microscopic anatomy of the esophagus including the individual layers, specialized tissues, and unique components and their responses to injury

“…A rich lymphatic network is present in the LP and is further concentrated in the SM. Several studies had suggested that lymphatics within the SM drains longitudinally along the submucosal plexuses up to its proximal ends (recurrent laryngeal nodes/supraclavicular node) or down to its distal ends (paracardial nodes/celiac nodes), bypassing the network in MP/adventitia and regional LNs. Direct drainage into the thoracic duct has also been documented in autopsy studies .…”

Failure patterns after adjuvant chemoradiotherapy following endoscopic resection for superficial esophageal squamous cell carcinoma

“…In this context, recurrent nerve lymph nodes are well known as frequent metastasis sites of thoracic esophageal squamous cell carcinoma . This is related to the submucosal lymphatic vessels running longitudinally along the thoracic esophagus, directly draining into the proximal and distal ends and consequently connecting the recurrent nerve and perigastric lymph nodes . Therefore, the locations of lymph node metastasis of SESCC exhibit a unique distribution to the recurrent nerve or perigastric lymph nodes, which can involve a solitary lymph node .…”

“…[21][22][23][24] This is related to the submucosal lymphatic vessels running longitudinally along the thoracic esophagus, directly draining into the proximal and distal ends and consequently connecting the recurrent nerve and perigastric lymph nodes. 25 Therefore, the locations of lymph node metastasis of SESCC exhibit a unique distribution to the recurrent nerve or perigastric lymph nodes, which can involve a solitary lymph node. 12,21,24,26 The perigastric lymph nodes are also known as frequent metastasis sites, especially for middle and lower thoracic esophageal cancer.…”

Genome‐wide analysis of long non‐coding RNAs in esophageal squamous cell carcinoma reveals their potential role in invasion and metastasis

“…Local relapse and regional lymphatic metastasis are important causes of failure after radical resection and irradiation of ESCC, leading to poor survival rates . Regional lymphatic metastasis of ESCC involves a wide region from the neck to the upper abdomen . Because of this pattern of lymphatic metastasis, it is difficult to remove and irradiate all regional lymph nodes via radical resection and irradiation, which can also have severe implications.…”