Incidental calcifying fibrous tumor of the stomach presenting as a polyp.

Calcifying fibrous tumor (CFT) is an uncommon lesion of uncertain cause and pathogenesis that has a unique histological appearance. These lesions are described mainly in the subcutaneous or deep soft tissues, followed by subserosal locations. Intrinsic visceral CFT is extremely rare. Herein is described a rare case of CFT that involved the gastric wall, along with a review of the literature. An incidental small polypoid lesion was excised during urgent surgery for penetrating injury at the lesser curvature in a 25-year-old man, previously healthy. The lesion was a well-demarcated, small (10 mm) tumor that occupied the submucosa. The characteristic histopathological features and the presence of spindle cells that express factor XIIIa allowed a diagnosis of CFT to be made. The present case and the review revealed that, despite their frequent subperitoneal location, intra-abdominal CFT might present as intrinsic visceral lesions and might be found incidentally. These lesions tend to be smaller when compared to their symptomatic counterparts. The diffuse factor XIIIa expression in CFT might be useful to differentiate this entity from other intra-abdominal soft-tissue tumors in problematic cases. Although rarity of intrinsic visceral CFT necessitates new cases to determine their exact biological behavior, the present case highlights their presence in the stomach as a symptomless small polypoid lesion.