Gastric mucosa infiltrated by an invasive carcinoma formed of lakes of extracellular mucin entangling sheets of malignant large epithelial cells having abundant vacuolated cytoplasm and hyperchromatic eccentric nuclei (signet ring forms) as well as tubular glands. Anaplasia and mitosis are moderate.
Prepyloric edematous mass.
Soft tissue fragments collectively measured 1 cm, totally embedded.
Stomach, endoscopic biopsy: