TY - CHAP M1 - Book, Section TI - Chapter 388. Abdominal Masses A1 - Densmore, John C. A1 - Oldham, Keith T. A2 - Rudolph, Colin D. A2 - Rudolph, Abraham M. A2 - Lister, George E. A2 - First, Lewis R. A2 - Gershon, Anne A. PY - 2011 T2 - Rudolph's Pediatrics, 22e AB - The abdominal mass in an infant or child is most commonly an incidental finding first observed by a parent or at the time of a pediatric screening examination. Over 50% of abdominal masses detected by physical examination are actually cases of organomegaly.1,2 The remaining 43% of masses require surgical evaluation and comprise neoplasms, developmental anomalies, and inflammatory or infectious disease. Ninety percent of this group are retroperitoneal masses, approximately half of which derive from the urinary tract.2 In neonates, multicystic dysplastic kidney and hydronephrosis occur in equal frequency and comprise 75% of abdominal masses.2 Older children are more likely to have neoplastic processes.2Table 388-1 lists the most likely diagnoses that vary by location of the mass and age group. SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/03/28 UR - accesspediatrics.mhmedical.com/content.aspx?aid=7035952 ER -