Selected topics in the evaluation of pediatric gastrointestinal mucosal biopsies.

The practice of pediatric gastrointestinal pathology provides specific challenges to the pathologist. Often the clinical information accompanying a biopsy specimen will read simply, "failure to thrive." Other situations, such as the evaluation of a neonate's rectal suction biopsy for Hirschsprung disease, are notorious for providing diagnostic challenges in high-pressure situations. In this review, we will discuss several commonly encountered situations in pediatric pathology: the evaluation of pediatric esophageal eosinophilia, a child who has swallowed a non food item, caustic substance, or hot liquid, the evaluation of a pediatric colorectal biopsy with focal active colitis, and the evaluation of rectal suction biopsies for Hirschsprung disease. With each topic, we will discuss a general approach to the case, diagnostic tips, and how to avoid commonly encountered pitfalls. Finally, we highlight key references pertinent to these issues that can he used to help convey pathologic findings to pediatric gastroenterologists.