<prompt> Most common type of gastric tumor in adults:AdenocarcinomaStromal tumorLeiomyosarcomaLymphoma  <response>: About 85 of stomach cancers are adenocarcinomas, with 15 due to lymphomas, gastrointestinal stromal tumors GISTs, and leiomyosarcomas. Gastric adenocarcinomas may be subdivided into two pathologically defined categories:Diffuse type, in which cell cohesion is absent, so that individual cells infiltrate and thicken the stomach wall without forming a discrete mass.Intestinal type, characterized by cohesive neoplastic cells that form gland-like tubular structures. The diffuse carcinomas occur more often in younger patients, develop throughout the stomach including the cardia, result in a loss of distensibility of the gastric wall so-called linitis plastica, or leather bottle appearance, and carry a poorer prognosis.Reference: Harrisons P R I N C I P L E S O F I N T E R N A L M E D I C I N E 20th edition page no 568 