Two Cases of Primary Gastric Adenocarcinoma with Enteroblastic Differentiation (ACED)

Abstract

The histopathology of adenocarcinoma with enteroblastic differentiation (ACED) is similar to gastrointestinal epithelium in the early embryonic period, and it is defined by positive expression of alpha-feto protein (AFP), Glypican3, or SALL4. Two cases of ACED are reported along with a review of the literature.

Case 1 : An 84-year-old man presented with an elevated AFP level and anorexia during hepatitis C treatment. He was diagnosed with a type 2 tumor of the gastric body and underwent distal gastrectomy. The histopathological findings showed moderate to poorly differentiated adenocarcinoma with a clear, rosette-like tubular structure, AFP+/SALL4+, which was diagnosed as ACED. The serum AFP level returned to the normal range seven months after surgery.

Case 2 : A 76-year-old man showed a CEA increase during follow-up after hepatocellular carcinoma surgery. He was diagnosed with type 3 gastric cancer and underwent total gastrectomy. The diagnosis of ACED was confirmed on histopathology : SALL4+ columnar cells with clear endoplasmic reticulum similar to fetal gastrointestinal epithelium. He has survived more than half a year and is currently undergoing adjuvant chemotherapy.