Polysplenia with situs inversus totalis, azygos continuation of the inferior vena cava, and duplication of the superior vena cava in a healthy adult: A case report

Polysplenia syndrome is an embryological disorder whereby the usual left-right asymmetry of thoracic and abdominal viscera fails to develop. It is a rare entity, estimated to occur at a frequency of 1 in 40,000, and is often associated with cardiac and biliary abnormalities. More than 75% of patients die before the age of 5 years, and even in the absence of cardiac anomalies, only 5%-10% of patients are expected to survive into adulthood without complications. Although polysplenia syndrome encompasses a wide range of anatomic abnormalities, there is no single pathognomonic feature. Hence, the prognosis of patients with polysplenia depends on their anatomy, thus necessitating radiology in their management. Here we present a case of a 56-year-old man with polysplenia syndrome and situs inversus totalis. This presentation is atypical because polysplenia is usually considered a form of situs ambiguus, and cases with situs inversus totalis are exceedingly rare. Also noted in our patient are variations in the great vessels, including aortic arch branches and the venae cavae which are features not typically associated with either polysplenia syndrome or situs inversus totalis. The patient is healthy and asymptomatic at baseline, with his diagnosis being made incidentally. Our case report is the first to describe this unique combination of cardiothoracic and cardiovascular anatomy. It also emphasizes the importance of radiologists in caring for patients with laterality defects. As these disorders are uncommon, more data on their anatomic variations may help provide better medical care to this patient population.