Sections show gastric mucosal fragments, with most of them showing a tubulovillous architecture, composed of crowded glands and villiform projections, displaying high grade dysplasia. In minor foci, there is transition to invasive poorly differentiated adenocarcinoma. This component is characterized by solid sheets, irregular nests, and discohesive single cells surrounded by dysmoplastic reaction. These cells exhibit marked nuclear pleomorphism, prominent nucleoli, and brisk mitotic activity, with no distinct gland formation. Rest of gastric mucosa shows chronic active gastritis.
Gastroesophageal junction tumor.
Soft tissue fragments collectively measured 0.9 cm, totally embedded.
Stomach, endoscopic biopsy: