Bronchopulmonary Variation in a Case of Situs Inversus Totalis

Abstract Background: Situs inversus totalis is the transposition of thoracic and abdominal internal organs across the sagittal plane. The incidence of situs inversus totalis is 1:10,000. This case of situs inversus totalis had variant bronchopulmonary laterality. Through extensive literature review we report no other documented cases of individuals with this anatomical variation. Case Information: This study involved detailed dissection of a 71-year-old male with situs inversus totalis and variant bronchopulmonary structures. This study serves to add to the expanding body of knowledge of situs inversus totalis and variations from the expected laterality. In the expected anatomy of individuals with situs inversus totalis, the right lung is bi-lobed and the left lung is tri-lobed. However, this case is exceedingly rare in that the individual maintained a tri-lobed right lung and bi-lobed left lung. In contrast to this, the cadaver maintained the expected situs inversus laterality of both hilar structures. The cadavers tri-lobed right lung maintained the pulmonary artery superior to the primary bronchus while the cadavers bi-lobed left lung possessed the pulmonary artery anterior to the primary bronchus. All other visceral findings were consistent with the expected laterality. Conclusions: As the cadaver maintained expected laterality of the bronchi and pulmonary arteries but did not maintain expected lung structure, we suggest that these findings may assist current research in determining the specific point in embryological development that laterality is determined. Clinicians, surgeons and radiologists should be aware of situs inversus totalis for diagnostic and therapeutic procedures and current clinical guidelines should take these rare variations into consideration.