[Lymph node metastasis in superficial squamous carcinoma of the esophagus]

The definition of early carcinoma of the esophagus has changed with time on the basis of new data. As from 2007 an early carcinoma is defined as an intramucosal carcinoma with or without metastasis. In the subclassification based on invasion depth, m1 and m2 squamous cell carcinomas have no metastasis and are considered curable by endoscopic resection alone, whereas less than 10% of m3 carcinomas and some 20% of sm1 squamous cell carcinomas have lymph node metastasis. In this article the relationship between various histopathological findings and the incidence of lymph node metastasis is reviewed. The m3 and sm1 superficial squamous cell carcinomas showing 0-I and 0-III types, large tumors over 50 mm in size or those showing vessel permeation have higher incidences of lymph node metastasis. In the field of gastrointestinal surgical pathology pathologists are now expected to not only diagnose the presence or absence of malignancy but also to investigate in detail many of the histological factors related to the prevalence of lymph node metastasis.