SPR Unknown # 74 -- FINAL

Tejal Patel,MD

Tamar Ben-Ami, MD

Childrens Memorial

Abstract

Newborn with bilateral pneumothoraces and pneumomediastinum.

Keywords

1176, Potter syndrome, Kidneys, absent, pneumothorax, newborn spr unknown 74, upcoming publication in: Casey JT, Cheng EY, & Donaldson J. “The adrenal gland.” In: Palmer LS & Palmer JS, editors. Pediatric and Adolescent Uroradiology. Springer Publishing, 2013.


Publication Date: 2006-07-06

History

Newborn that was delivered at home. Mother had no prenatal care. Newborn presents with bilateral pneumothoraces and is transferred from an outside hospital with a clinical suspicion of a "mediastinal mass".

Findings

Babygram Supine, AP demonstrated a large pneumomediastinum elevating the prominent thymus, which mislead the initial interpreters to call it a thoracic mass. The thorax is bell-shaped. Bilateral chest tubes are prsent. The lung volumes are very small suggestive of pulmonary hypoplasia

Ulstrasound image 1 demonstrates no kidney in the left renal fossa. A normal spleen and adrenal are identified. Images 2&3 show linear echogenic structure anterior to the prominent neonatal uterus, which may represent a bladder remnant, otherwise there was no evidence of a definite bladder. Image 4 demonstrates no kidney in the right upper quadrant. Normal liver and adrenal are present.

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Diagnosis

Potter's syndrome with bilateral renal agenesis.

DDx

Potter syndrome secondary to oligohydraminos from bilateral renal agensis and prenatal renal failure. Other causes of Potter-like syndrome include Bladder outlet obstructions such as posterior urethral valves, other urethral obstructions (anterior uerthral valves, congenital megalourethra) in the male and prolapsing ectopic ureterocele in both sexes, more common infemales, prune belly syndrome, polycycstic kidney disease, mostly autosomal recessive, severe obstructive anomaly of a solitary kidney. Chronic amniotic leak leading to oligohydramnios can result in pulmonary hypoplasia and bilateral pneumothoraces.

Discussion

Potter's syndrome was originally described as bilateral renal agenesis with pulmonary hypoplasia and multilple contractures and dislocations as well as a typical facies. The typical physical appearnce is the result of oligohydraminos, secondary to renal insufficiency in utero. Other causes of renal failure in the fetus may result in Potter-like syndrome. These include obstructive uropathy, predominantly bladder outlet obstruction, prune belly syndrome, autosomal recessive polycystic kidney disease, and other. Less severe forms are called Potter sequence. The Potter facies is described as a flattened nose, recessed chin, promineny epicanthal folds and low set abnormal ears. In addition to these features, some have excessively lax skin and limb positioning defects. Our patient did have the flattened noses and recessed chin.

Normally the fetus continously swallows amniotic fluid which is reabsorbed by the gastrointestinal tract and then reintroduced into the amniotic cavity by the kidneys. Oligohydraminos results from decreased urine production secondary to bilateral renal agenesis, obstruction of urinary tract or prolonged rupture of membranes.

Bilateral renal agenesis occurs in 1 in per 3000 births and responsible for 20% of Potters syndrome. Potter syndrome is usually fatal in the first few days of the patient's life. Most often the cause is pulmonary failure. Causes of Potter syndrome include bilateral renal agenesis, infantile polycystic kidney disease, posterior urethral valves, and early rupture of membranes. Males have an increased incidence of Potter sequence. If mother had prenatal care the ultrasound would depict renal agensis and oligohydraminos. Prenatal Doppler ultrasound can be helpful in depicting fetal pulmonary hypoplasia. Neonatal imaging studies: Abdominal Ultrasound demonstrates the renal disease and evaluates the ureters and bladder. Chest radiography reveals spontaneous pneumothrax and pulmonary hypoplasia as was seen in our patient.

Pulmonary hypoplasia depends on the degreee and duration of oligohydraminos. Skeletal malformations such as hemivertebrae, sacral agenesis and limb anolmaies may be present.

Renal fucntion and respiratory status of the neonates born with Potter syndrome must be assessed. Assoicated anomalies of GI, cardiovascular, and musculoskeletal systems should be evaluated.

Further treatment is usually not indicated in neonates with bilateral renal agenesis and severe neonatal respiratory distress due to pulmonary hypoplasia and spontaneous pneumothorax. In milder forms - renal transplant may be performed if the lungs can sustain life and some renal function plus dialysis allow the patient time to grow and become a reasonable candidate

References

  1. Caffey's Pediatric Diagnostic Imaging, Kuhn, Jerald P. MD, Slovis, Thomas L. MD, Haller, JAck O. MD. 1768-1770, 2004.
  2. Radiology of Syndromes, Metabolic Disorders, and Skeletal Dysplasias. Taybi, Hooshang MD and LAchman Ralph S. MD, 4th edition pg 399,1996.

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