Selected topics in pediatric pathology

While much perinatal gastrointestinal pathology is concerned with confirmation of diagnoses, such as necrotizing enterocolitis, meconium ileus and intestinal atresia in surgically resected specimens, there are two clinical situations in the neonatal period in which the primary diagnosis rests with the histopathologist. The first is constipation (which usually presents as delayed passage of meconium) in which a rectal suction biopsy is required to confirm or exclude the diagnosis of Hirschsprung’s disease. The second is congenital diarrhea, in which a small bowel biopsy is performed to confirm or rule out a number of specific disease entities, chief among which are microvillus inclusion disease, tufting enteropathy and autoimmune enteropathy.