In 1950, Sullivan reported one case of sicklemia trait with sudden splenic enlargement following an airplane flight.1 This case report was reviewed by Margolies2 in 1951 in his comprehensive review of the literature on sickle cell anemia. He states that it was difficult to believe that the splenic enlargement in this sicklemic patient was secondary to low oxygen tension in high altitude flying. He felt that this single case was inadequate proof of any specific relationship between sicklemia and high altitude flying.
The purpose of this report is to add to the literature six additional cases of splenic enlargement and infarction in high altitude flight. In five of these cases there was definite sickling in peripheral blood on cysteine preparation,3 while in one case sickling could be demonstrated only in the pathological specimen.
In the six cases reported there was a remarkably similar clinical pattern. All the