Polysplenia syndrome

Polysplenia syndrome, also known as left isomerism, is a type of heterotaxy syndrome where there are multiple spleens congenitally as part of left-sided isomerism.

Epidemiology

Polysplenia is seen predominantly in female patients. It is usually diagnosed in childhood or adulthood, later than asplenia syndrome, since associated congenital heart diseases tend to be less severe than those encountered in the latter.

Etiology

The exact cause of polysplenia is unknown. However it is suggested that it is caused by various factors :

• embryogenic
• genetic
• teratogenic 

Clinical manifestation

Clinical presentation is related to the associated pathology.

Pathology

Polysplenia results from failure of development of the usual left-right asymmetry of organs and consists of situs ambiguus, with features of bilateral left-sidedness.

Radiographic features

General

It is characterized by multiple splenules without a parent spleen. It occurs on the patient’s left side but may be bilateral. The most common associated feature is inferior vena cava interruption with azygos or hemiazygos continuation .

Other characteristic features include:

• bilateral hyparterial bronchi
• bilateral bilobed lungs
• bilateral pulmonary/left atria
• midline liver

Associations

• congenital heart disease (>50%): especially non-cyanotic, and less complex/severe than in asplenia syndrome 
  • abnormal pulmonary venous return (70%, PAPVR/TAPVR)
  • dextrocardia (37%)
• gastrointestinal
  • semi-annular pancreas / congenitally short pancreas 
  • midgut malrotation (80%) 
  • gallbladder agenesis (50%) and biliary atresia
  • mobile cecum
  • tracheo-esophageal fistula
• genitourinary
  • renal cyst
  • renal agenesis
  • ovarian cyst
• vascular
  • inferior vena cava anomalies
    • ​intrahepatic IVC interruption with azygos/hemiazygos continuation
  • portal vein anomalies
    • preduodenal portal vein

See also

• asplenia syndrome
• heterotaxy syndrome
• situs classification
• isomerism

Siehe auch:

• Lungenvenenfehlmündung
• Azygoskontinuität
• Herzfehler
• Splenose
• Nebenmilz
• intestinale Malrotation
• Pancreas anulare
• Situs ambiguus
• einseitige Nierenagenesie
• situs classification
• mobile cecum
• congenital tracheoesophageal fistula
• Gallengangatresie
• congenitally short pancreas
• fokale Milzläsionen und Anomalien
• asplenia/polysplenia
• Gallenblasenagenesie

und weiter:

• Abernethy malformation
• Agenesie der dorsalen Pankreasanlage
• kurzes Pankreas