Situs Ambiguus - Presentation

Presentation

Classically, it comprises:

• Cardiac looping malformations – commonly Fallot’s tetralogy, transposition of the great vessels, pulmonary valve stenosis, and ventricular and atrial septal defects.
• Deranged abdominal organ asymmetry - the stomach and spleen are particularly prone to isolated reversal, and the stomach, liver, and a single adrenal gland are occasionally found in the midline.
• Organ malformations - chiefly asplenia-polysplenia, and more rarely a failure of the head of the pancreas to form, and horseshoe adrenals and kidneys.
• Rotation errors, causing volvulus and/or faulty peritoneal attachments.

More rarely, vascular abnormalities are found, including interrupted inferior vena cava, bilateral superior or inferior venae cavae, intrahepatic interruption of the inferior vena cava with connection to the azygos or hemiazygos veins, and aberrant portal veins.