Polysplenia syndrome

Last revised by Rohit Sharma ◉ on 15 Aug 2023

Citation, DOI, disclosures and article data

Citation:

Niknejad M, Sharma R, El-Feky M, et al. Polysplenia syndrome. Reference article, Radiopaedia.org (Accessed on 21 Sep 2023) https://doi.org/10.53347/rID-21610

DOI:

https://doi.org/10.53347/rID-21610

Permalink:

https://radiopaedia.org/articles/21610?iframe=true

rID:

21610

Article created:

3 Feb 2013, Mohammadtaghi Niknejad ◉

Disclosures:

At the time the article was created Mohammadtaghi Niknejad had no recorded disclosures.

View Mohammadtaghi Niknejad's current disclosures

Last revised:

15 Aug 2023, Rohit Sharma ◉

Disclosures:

At the time the article was last revised Rohit Sharma had no financial relationships to ineligible companies to disclose.

View Rohit Sharma's current disclosures

Revisions:

31 times, by 18 contributors - see full revision history and disclosures

Systems:

Gastrointestinal, Cardiac, Paediatrics

Sections:

Anatomy, Syndromes

Tags:

syndrome, variant

Synonyms:

Left isomerism
Polysplenia
Bilateral left-sidedness
Left sided isomerism

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.

congenital heart disease (>50%): especially non-cyanotic, and less complex/severe than in asplenia syndrome ³
- abnormal pulmonary venous return (70%, PAPVR/TAPVR)
- dextrocardia (37%)
gastrointestinal
- semi-annular pancreas / dorsal pancreatic agenesis ^4,6,8
- midgut malrotation (80%) ^7,8
- gallbladder agenesis (50%) and biliary atresia
- mobile cecum
- tracheo-esophageal fistula
- absent C-loop of duodenum
genitourinary
vascular
- inferior vena cava anomalies ^7,8
  - intrahepatic IVC interruption with azygos/hemiazygos continuation
- portal vein anomalies ^7,8
  - preduodenal portal vein

Clinical presentation

It 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.

Etiology

The exact cause of polysplenia is unknown. However, it is suggested that it is caused by various factors ¹⁰:

embryogenic
genetic
teratogenic

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 ³.

Other characteristic features include:

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

Treatment and prognosis

It carries 75% mortality by age 5 though. The presence of congenital heart diseases increases mortality rate. 1-year mortality is approximately 85% with right isomerism and more than 50% with polysplenia syndrome as the latter has less association with congenital heart diseases ¹¹.