The sickle cell trait in relation to the training and assignment of duties in the armed forces: II. Aseptic splenic necrosis.

Well-documented information gleaned from the world's literature reveals that in vivo sickling of erythrocytes and vascular occlusive lesions involving the spleen have occurred in individuals with the sickle cell trait (SCT) while flying in unpressurized airplanes or when exposed to hypoxic environments in mountains at intermediate altitudes. The clinical and anatomical manifestations of splenic infarcts are described. Individuals without the trait do not develop splenic infarcts during or following exposure to ambient hypoxia.