Peridiverticular colonic hyaline rings (pulse granulomas): report of two cases associated with perforated diverticula.

Hyaline ring (pulse granuloma) is a rare benign lesion of the oral cavity soft tissues characterized by round or oval structures with scalloped borders composed by a collagenous matrix variable associated with inflammatory and foreign bogy giant cells. Vegetable fragments are variably identified. Whereas most cases occur in the oral cavity, it has also been described in other sites such as the lung and rectum. It is thought by most to represent a reaction to foreign materials. We report two incidentally discovered cases of colonic hyaline rings associated with perforated diverticulitis. Vegetable residues were seen in both cases.