Lymphatic invasion according to D2-40 immunostaining is a strong predictor of nodal metastasis in superficial squamous cell carcinoma of the esophagus: algorithm for risk of nodal metastasis based on lymphatic invasion.

In squamous cell carcinoma (SCC) of the esophagus, D2-40 immunostaining has recently been used to detect lymphatic invasion, but invasion detected using D2-40 immunostaining for a predictor of nodal metastasis was controversial. Therefore, the usefulness of detecting lymphatic invasion by D2-40 immunostaining as a predictor of nodal metastasis was examined in superficial (mucosal and submucosal) SCC of the esophagus. A total of 115 superficial SCC of the esophagus were examined on immunohistochemistry using D2-40. It was found that lymphatic invasion demonstrated on D2-40 immunostaining was mainly detected in the lamina propria mucosa. Lymphatic invasion was found in 37 cases and the invasion detected in the entire tumor tissue was statistically correlated with nodal metastasis. Based on the lymphatic invasion according to D2-40 immunostaining, an algorithm was devised for the risk (low, intermediate and high) of nodal metastases in superficial SCC in the esophagus. In conclusion, the detection of lymphatic invasion on D2-40 immunostaining in tumor tissue is a strong predictor for nodal metastasis in superficial SCC of the esophagus. Lymphatic invasion was found mainly in the lamia propria mucosa, thus the devised algorithm is useful for determining the optimal treatment strategy after endoscopic mucosal resection for esophageal SCC.