Gastrointestinal stromal tumors of the stomach with extensive calcification: report of two cases.

Gastrointestinal stromal tumors (GISTs) can present with focal calcification. However, the presence of extensive calcification that constitutes the major portion of a GIST is extremely rare and can be associated with diagnostic pitfalls. We herein present the first two cases of rare gastric GIST with predominantly calcified components that mimicked pancreatic solid and pseudopapillary neoplasms with extensive calcification. In patients presenting with hyper-dense, heavily calcified masses in the abdominal cavity, the possibility of GIST should be considered in the differential diagnosis. A careful search for cellular areas and the judicious application of immunostaining will thus make it possible to make a correct diagnosis.