A case of superficial esophageal cancer invading into the submucosa following ductal involvement with microinvasion.

Microinvasion is considered one reason for diagnostic discrepancies among preoperative diagnostic modalities. Stromal invasion developing from ductal involvement is often observed in such cases. Herein, we present a case of superficial esophageal cancer with ductal involvement and microinvasion around it. The steep concavity with dot-like microvessels in the center of a protruded lesion was presented by endoscopic observation, which was lead to the diagnostic discrepancy between magnified endoscopy and endoscopic ultrasound. Histological findings showed the tumor invaded into a submucosal layer with ductal involvement and microinvasion around it, and confirmed that this endoscopic finding was caused be tumor ductal involvement. When encountering endoscopic findings similar to those shown in this case, preparation of serial sections, enabling the confirmation of ductal involvement and further invasion into the stroma, will lead to the accurate diagnosis.