Abstract
A total of thirty-two autopsy cases of the so called splenic agenesis syndrome (or Ivemark’s syndrome) were collected and studied pathomorphologically. The splenic agenesis syndrome is composed of three main elements; namely, congenital splenic agenesis, characteristic anomalies of the cardiovascular system, and abdominal heterotaxy with right sidedness of the visceral organs. The cases were classified into three types according to severity of these anomalies; complete (having all these three components), incomplete (asplenia and one of the other two), and simple (only congenital absence of the spleen). Anomalous pulmonary venous return and abnormality of the efferent hepatic veins, both of which were occasionally seen associated in this syndrome, seem to give some influence on the survival period of patients. As for the secondary changes caused by these cardiovascular anomalies, mild hypoplasia of the media, fibrous thickening of the intima, and thrombus formation in the lumen due to stenosis or arteria of the pulmonary trunk were frequently found in the small pulmonary arteries. Various changes of the so-called morbus caeruleus were observed in the liver, kidney, etc. As a possible, compensatory reaction to congenital absence of the spleen, the lymph follicles were found appearing in the bone marrow about one year after birth. Infectious changes were observed, as the direct cause of death, in five cases, all of which were below one year of age.
