Gastric adenocarcinoma with hepatoid or enteroblastic differentiation (GAHED), known also as AFP-producing carcinoma, is a rare neoplasm. Ten cases with GAHED and 209 cases without GAHED were selected. Clinicopathological features of GAHED were investigated. The disease-free survival (DFS) of the GAHED group was compared with that of the non-GAHED group. Grossly, the tumours consisted of two early types and eight advanced types. Histologically, all tumours were composed of various proportions of tubular, cribriform, papillary, solid, and/or trabecular growth patterns of clear to slightly eosinophilic tumour cells. Hyaline globules were observed in all tumours. AFP and Hep-Par1 were immunoreactive in all tumours. In fluorescence in situ hybridisation of HER2 gene/chromosome 17, the amplification of HER2 gene was observed in two cases that showed positive reaction for HER2 protein. Clinical follow-up was available in nine cases. Regarding the clinical outcome, 3 and 6 patients were alive without disease and alive with disease, respectively. In a statistical analysis, the DFS of the GAHED group was significantly worse than that of the non-GAHED group.
GAHED is morphologically characterised by various growth patterns of clear to slightly eosinophilic tumour cells and intracytoplasmic possession of hyaline globules. This tumour may have the potential to behave in an aggressive clinical fashion.