Familial gastric cancer (Orphanet_26106, an Orphanet rare-disease nomenclature entry) is an autosomal dominant inherited adenocarcinoma that arises from the gastric mucosa and is characterized by the presence of poorly cohesive malignant cells and absence of glandular formations. Also known as: FDGC, HDGC, familial diffuse cancer of stomach, familial diffuse gastric cancer, hereditary diffuse cancer of stomach, hereditary diffuse gastric adenocarcinoma, hereditary diffuse gastric cancer.