Bone metaplasia in a rectal polyp

A 77-year-old male underwent a colonoscopy because of a positive fecal occult blood test. A polyp was removed from the rectum, 12 cm from the anal margin, with a hyperplastic appearance, covered by a cap of whitish fibrinoid exudate. The pathological report reported a hyperplastic polyp with foci of bone metaplasia in the lamina propria.