NCIt definition : An adenocarcinoma that arises from the gastric mucosa and is characterized by the
presence of isolated malignant cells or malignant cells that form small aggregates.
This category includes signet ring cell adenocarcinomas, adenocarcinomas that are
composed of malignant cells resembling lymphocytes and histiocytes, and adenocarcinomas
that are composed of malignant cells with deeply eosinophilic cytoplasm.;