Figure 1  .

Measurement of tumour area, by endoscopic ultrasonography (EUS), and pathological tumour volume. (A) Ultrasound probe image of submucosal cancer. The ultrasound probe reveals a hypoechoic mass region extensively invading into the high echoic third layer (submucosal layer). In this case, the EUS area of the tumour was 36.1 mm². (B) Histological findings after surgery showed the tumour limited to the submucosa (haematoxylin-eosin, original magnification). Pathological tumour volume (cm³) is the total tumour area (a+b+c+d) (cm²)×width of prepared specimen (0.4 cm) In this case, the pathological tumour volume was 3.20 cm³.