Early Gastric Cancer with Purely Enteroblastic Differentiation and No Conventional Adenocarcinoma Component

Abstract

Gastric carcinoma with enteroblastic differentiation (GCED) is a rare variant of gastric carcinoma, and a part of GCED produces alpha-fetoprotein. GCED is characterized by cells with clear cytoplasm and a tubulopapillary and solid growth pattern resembling those in the primitive gut. GCED is typically overlaid by a conventional adenocarcinoma (CA) component, implying that CA in the mucosa differentiates into GCED during tumor invasion and proliferation. We present the case of a 73-year-old woman with a 10-mm superficial elevated lesion and a slight central depression at the anterior wall of the lower gastric body. Endoscopic submucosal dissection revealed tumor cells having clear cytoplasm and severely atypical nuclei characteristic of GCED. The growth pattern was predominantly solid and trabecular but included submucosal layer invasion and limited tubular growth. Atrophic pyloric mucosa without intestinal metaplasia surrounded the tumor. Immunohistochemically, the tumor cells were positive for AFP, GPC3, and SALL4. The present patient showed a purely enteroblastic differentiation without a CA component despite the presence of early cancer, indicating that few cases of GCED may arise de novo in the gastric mucosa. GCED is more aggressive compared with CA; therefore, pathologists should be aware that GCED without CA can appear in biopsy specimens of early cancer while making an accurate diagnosis.

Cytopathological features of gastroesophageal junction adenocarcinoma with enteroblastic differentiation and histopathological correlation

“…Histologically, the tumour cells are columnar or cuboidal with clear cytoplasm containing abundant glycogen and a tubulopapillary architecture. 6,7 The abundance of glycogen and clear cell morphology may impart a somewhat tigroid (granular, reticulated) background on Romanowsky-based stains, as was evident in our case. On IHC, the tumour cells are known to express several oncofetal proteins, including AFP, SALL4, and glypican-3.…”

“…Anisocytosis, nuclear contour irregularity, and prominent nucleoli are key features. Histologically, the tumour cells are columnar or cuboidal with clear cytoplasm containing abundant glycogen and a tubulopapillary architecture 6,7 . The abundance of glycogen and clear cell morphology may impart a somewhat tigroid (granular, reticulated) background on Romanowsky‐based stains, as was evident in our case.…”

Pathologically diagnosed early‐stage gastric adenocarcinoma with enteroblastic differentiation after endoscopic submucosal dissection: A case report

“…They are classified by images of hematoxylin and eosin staining and immunostaining, and SALL4 and Glypican3 are known as sensitive markers for the diagnosis of not only AFPGC but also GAED. 4,5 In our case, the microscopic pathological image with hematoxylin and eosin staining revealed tumor cells with pale cytoplasm, and in addition to AFP, the immunostaining of SALL4 and Glypican3 was positive. For endoscopists, pathological specimen confirmation and discussion with a pathologist are important for diagnosing AFP-producing early-stage gastric cancer.…”

“…AFP-producing early-stage gastric cancer was reported in 47 patients from 1990 to 2022, including our cases (Table 1). [3][4][5][6][7][8][9][10] Additionally, we could not find reports regarding early-stage cases of AFP-producing gastric cancer outside of Japan. The gross type was IIa+IIc/IIc+IIa in 23 cases (49%), and the histological types were por, tub2, and tub1, in that order.…”

Case Report: Primary pure clear cell gastric carcinoma

“…Kim et al 7 reported 65 cases and defined CCC as a carcinoma composed of more than 5% of clear cells. To the best of our knowledge, only Terada 9 and Yamada et al 10 have reported the pure form.…”