Lymphoid follicular pattern: a normal feature of the pediatric colon.

Tiny nodular filling defects up to 2 mm in diameter were seen in 12 of 27 patients under the age of 15 years undergoing double contrast enema. The pattern was particularly common in children under 5 years in whom a good quality double contrast study was obtained. While this pattern has been termed lymphoid hyperplasia, we believe it represents a normal lymphoid follicular pattern in the pediatric colon. The term lymphoid hyperplasia should be reserved for cases in which the lymphoid follicles are greater than 2 mm in diameter; this will usually represent an abnormal condition in response to infection, allergy, or immunologic disorders. The differential diagnosis of the lymphoid follicular pattern and lymphoid hyperplasia is briefly discussed.