Splenic sequestration in the adult: cross sectional imaging appearance of an uncommon diagnosis

Acute splenic sequestration crisis, the sudden pooling of red blood cells in the spleen, is an emergent process typically seen in children with homozygous sickle cell disease. Splenic sequestration has rarely been reported in adults with heterozygous sickle cell conditions, including sickle cell beta(+)-thalassemia disease (HbS/β⁺-thalassemia). Here we present a case of a 32-year-old man with HbS/β⁺-thalassemia who suffered an acute splenic sequestration crisis. We review the CT and ultrasound appearance of splenic sequestration, which include splenic enlargement and an irregular rim of hypoenhancing or hypoechoic tissue at the periphery of the spleen, and discuss imaging differential considerations. To our knowledge, this is only the nineteenth case of acute splenic sequestration to be reported in an adult with HbS/β⁺-thalassemia in the English literature, and only the second case in which ultrasound findings are reported.