[Pathology of endoscopic submucosal dissection; how do we interpret?].

It is widely accepted that endoscopic submucosal dissection (ESD) is an important treatment option for cases of early gastric carcinoma where the probability of lymph node metastasis is very low. The resected ESD specimens are carefully examined by serial sections at 2 mm intervals, and if pathology reveals submucosal invasion more than 500 μm and/or lymphovascular invasion, or if the resection margin is involved by the tumor, surgery is recommended. In this point of view, thorough pathologic examination and reporting the accurate pathologic diagnosis of ESD specimen is very important. The diagnostic approach and pitfalls in the diagnosis of ESD specimen are reviewed.