Asplenia and polysplenia syndrome.

This report described the morphological characteristics of seven cases of asplenia syndrome and three of polysplenia syndrome. Each syndrome has been characterized by a tendency for symmetric development of normally asymmetric organs, with varying degrees of cardiovascular anomalies. These latter anomalies are usually present in asplenia syndrome to a greater extent than in polysplenia syndrome. While, as observed in our material, the conotruncal anomalies were present more commonly in cases with asplenia, and absence of inferior vena cava with azygos continuation was seen specifically in all the cases with polysplenia. This evidence implied the presence of some pathogenetic distinction between the two syndromes.