Howell-Jolly body

Overview
Howell-Jolly bodies are histopathological findings of basophilic nuclear remnants (clusters of DNA) in circulating erythrocytes. During maturation in the bone marrow erythrocytes normally expel their nuclei, but in some cases a small portion of DNA remains. This DNA appears as a basophilic (purple) spot on the otherwise eosinophilic (pink) erythrocyte on a standard H and E stained blood smear. These inclusions are normally pitted out by the spleen during erythrocyte circulation, but will persist in individuals with functional hyposplenia or asplenia. Common causes of asplenia are splenectomy due to trauma, and autosplenectomy caused by sickle cell anemia. Other causes are radiation therapy involving the spleen, such as that used to treat Hodgkin lymphoma.

Howell-Jolly bodies are also seen in severe hemolytic anemia, megaloblastic anemia, hereditary spherocytosis, and myelodysplastic syndrome (MDS).