Anomalies of lateralization in man: a case of total situs inversus

Total or complete visceral situs inversus is the complete inversion of posi tion of the thoracic and abdominal viscera. The aim of this study is to rep ort a case of complete situs inversus and to review our knowledge of the an omalies of lateralization. A case of complete sinus inversus was discovered incidentally during anatomic dissection in a female subject aged 87 years. The thoracic and abdominal organs had a position symmetric with the normal . This was associated with a common mesentery and incomplete rotation of th e colon, placing the cecum under the left lobe of the liver. These alimenta ry anomalies were discovered in adult life during a surgical operation for small intestinal occlusion, as evidenced by the abdominal scar and peritone al adhesions. No cardiac, pulmonary, splenic or facial sinus anomalies were encountered. The incidence of complete situs inversus is estimated as 1/80 00 in the general population. It may be isolated or associated with malform ations, especially cardiac or alimentary. It may be discovered in infancy b ecause of associated anomalies but often remains asymptomatic and discovere d by chance in adult life. Complete situs inversus may form part of the mul tiple malformational syndromes such as that of Kartagener, with recessive a utosomal transmission (complete situs inversus, bronchiectasis, chronic sin usitis, male infertility), which represents 20-25% of cases of complete sit us inversus. In view of the frequency of this type of anomaly, a knowledge of anomalies of lateralization is essential in clinical practice.