Pyloric stenosis
Pyloric stenosis Description Hyperplasia (increased mass) and hypertrophy (increased size) of the circular and longitudinal muscle layers at the pylorus, which narrows the pyloric canal (see Understanding pyloric stenosis, page…
Patent ductus arteriosus
Patent ductus arteriosus Description Heart condition in which the lumen of the ductus (fetal blood vessel connecting the pulmonary artery to the descending aorta) remains open after birth (see Anatomy…
Otitis media
Otitis media Description Inflammation of the middle ear associated with fluid accumulation Peaks between ages 6 and 24 months Subsides after age 3 Occurs most commonly during winter months Can…
Osteogenic sarcoma
Osteogenic sarcoma Description Most common bone cancer in children Peak age late adolescence; rare in young children Usually involves the diaphyseal long bones; about 50% of cases occur in femur…
Osteogenesis imperfecta
Osteogenesis imperfecta Description Genetic disease in which bones are thin, poorly developed, and fracture easily Expression dependent on whether defect is carried as a trait or clinically obvious Autosomal dominant…
Non-Hodgkin’s lymphoma
Non-Hodgkin’s lymphoma Life-threatening disorder Description Includes lymphosarcoma, reticulum cell sarcoma, and Burkitt’s lymphoma Prognosis for aggressively treated localized disease: nearly 90% survival; for advanced disease, survival greater than 60% Also…
Neuroblastoma
Neuroblastoma Life-threatening disorder Description Most common extracranial solid tumor diagnosed in infancy Usually arises from the adrenal gland but may also arise at multiple sites, usually within the abdomen Usually…
Neural tube defects
Neural tube defects Description Birth defects that involve the spine or skull Result from neural tube’s failure to close approximately 28 days after conception Spina bifida (50% of cases), anencephaly…
Nephrotic syndrome
Nephrotic syndrome Description Kidney disorder characterized by marked proteinuria, hypoalbuminemia, hyperlipidemia, increased coagulation, and edema Results from a glomerular defect that affects permeability, indicating renal damage Prognosis highly variable, depending…
Muscular dystrophy
Muscular dystrophy Description Hereditary disorder characterized by progressive symmetrical wasting of skeletal muscles No neural or sensory defects Four main types: Duchenne’s (pseudohypertrophic), Becker’s (benign pseudohypertrophic), Landouzy-Dejerine (facioscapulohumeral), and Erb’s…
