Coexistence of Gastric Cancer and Multiple Small Gastrointestinal Stromal Tumors: Report of a Unique Case and Review of the Literature.

Background: In recent years, the synchronous occurrence of tumors of different histotypes arising in the same organ has been reported more frequently in the literature. The simultaneous development of adenocarcinoma and gastrointestinal stromal tumor (GIST) has been documented rarely.

Summary: The coexistence of primary gastric adenocarcinoma and GIST has been detected incidentally on gastric mucosa, serosa or occasionally intramurally, at surgery, or gastroscopy for other reasons. We present a case of a 79-year-old male patient who underwent surgery for an advanced gastric carcinoma, where multiple nodules of GIST were incidentally discovered during the work-up of his gastrectomy specimen.

Key message: GISTs range from small "low-risk" tumors to sarcomas. Small GISTs are found incidentally during unrelated surgery or autopsy. Multiple GISTs are extremely rare and usually associated with hereditary diseases.

Practical implications: In any case of gastrointestinal neoplasm, the surgeon and pathologist should be alert to perform a thorough investigation. Our case could provide further awareness and insight into the entity of concurrent tumors.