Synchronous primary adenocarcinoma and gastrointestinal stromal tumor in the stomach: a report of two cases.

Synchronous occurrence of epithelial and gastrointestinal stromal tumors (GISTs) in the stomach is uncommon. This association has often been detected incidentally on gastric mucosa or serosa, or occasionally intramurally, at surgery or gastroscopy for other reasons. Various hypotheses have been proposed regarding this simultaneous development, and it is not known whether or not such an association is a simple incidental coexistence or whether the two lesions are connected by a causal relationship.