A case of lymph node metastasis after endoscopic mucosal resection of esophageal cancer invading the muscularis mucosa

A 70-year-old man was diagnosed with a thoracic esophageal squamous cell carcinoma invading the muscularis mucosa without lymph node or distant metastases in June 2003. Endoscopic mucosal resection was conducted. Histological examination showed squamous cell carcinoma invading the deep mucosal layer without lymphatic permeation. In April 2006, a chest CT scan revealed a metastasis to the right recurrent laryngeal nerve chain (106recR) lymph node, and chemoradiotherapy and chemotherapies were performed but were not very effective. He died of esophagobronchial fistula in October 2007. We reexamined this case in detail, and a deeper cut of the block revealed positive lymph vessel invasion and droplet infiltrations. We were initially unable to identify lymphatic permeation but specific findings were determined, such as high degrees of cellular atypia, downward extension of irregular epithelial processes, and irregular margins of cancer alveoli. Extreme caution is required for treating patients with these morphological changes.