Calcifying fibrous tumor of small intestine.

Calcifying fibrous tumor (CFT) is a rare benign tumor with a predilection for children and young adults that usually arises in the subcutaneous and deep soft tissues, pleura, or peritoneum. It presents histologically as a well-circumscribed mass consisting of hyalinized, hypocellular lamellar collagen, bland spindle cells, chronic inflammatory cell infiltrates, and psammomatous or dystrophic calcifications. Calcifying fibrous tumor of the gastrointestinal tract is exceedingly rare and therefore prone to confusion with other spindle cell lesions more commonly encountered in this location. We describe 4 cases of calcifying fibrous tumor arising in the terminal ileum, one of which caused the heretofore unreported complication of intestinal intussusception, and discuss the differential diagnosis with other common and uncommon spindle cell lesions.