A Howell–Jolly body is a

cytopathological Cytopathology (from Greek , ''kytos'', "a hollow"; , ''pathos'', "fate, harm"; and , ''-logia'') is a branch of pathology that studies and diagnoses diseases on the cellular level. The discipline was founded by George Nicolas Papanicolaou in 19 ...

finding of basophilic

nuclear Nuclear may refer to: Physics Relating to the nucleus of the atom: * Nuclear engineering *Nuclear physics *Nuclear power *Nuclear reactor *Nuclear weapon *Nuclear medicine *Radiation therapy *Nuclear warfare Mathematics *Nuclear space *Nuclear ...

remnants (clusters of DNA) in circulating erythrocytes. During maturation in the

bone marrow Bone marrow is a semi-solid tissue found within the spongy (also known as cancellous) portions of bones. In birds and mammals, bone marrow is the primary site of new blood cell production (or haematopoiesis). It is composed of hematopoietic ce ...

, late erythroblasts normally expel their nuclei; but, in some cases, a small portion of DNA remains. Its presence usually signifies a damaged or absent spleen, because a healthy spleen would normally filter this type of red blood cell. The Howell–Jolly body is named after

William Henry Howell William Henry Howell (February 20, 1860 – February 6, 1945) was an American physiologist. He pioneered the use of heparin as a blood anti-coagulant. Early life William Henry Howell was born on February 20, 1860, in Baltimore, Maryland. He gra ...

and Justin Marie Jolly.

Appearance

This DNA appears as a basophilic (purple) spot on the otherwise eosinophilic (pink) erythrocyte on a standard

H&E stain Hematoxylin and eosin stain ( or haematoxylin and eosin stain or hematoxylin-eosin stain; often abbreviated as H&E stain or HE stain) is one of the principal tissue stains used in histology. It is the most widely used stain in medical diagnos ...

ed blood smear. These inclusions are normally removed by the

spleen The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes .

during erythrocyte circulation, but will persist in individuals with functional

hyposplenia Asplenia refers to the absence of normal spleen function and is associated with some serious infection risks. Hyposplenism is used to describe reduced ('hypo-') splenic functioning, but not as severely affected as with asplenism. ''Functional'' a ...

asplenia Asplenia refers to the absence of normal spleen function and is associated with some serious infection risks. Hyposplenism is used to describe reduced ('hypo-') splenic functioning, but not as severely affected as with asplenism. ''Functional'' a ...

Causes

Howell–Jolly bodies are seen with markedly decreased splenic function. Common causes include asplenia (post-splenectomy) or congenital absence of spleen (right atrial appendage isomerism). Spleens are also removed for therapeutic purposes in conditions like hereditary spherocytosis, trauma to the spleen, and

autosplenectomy An autosplenectomy (from'' 'auto-' ''self,'' '-splen-' ''spleen,'' ' -ectomy' ''removal) is a negative outcome of disease and occurs when a disease damages the spleen to such an extent that it becomes shrunken and non-functional. The spleen is an im ...

caused by sickle cell anemia. Other causes are

radiation therapy Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radia ...

involving the spleen, such as that used to treat

Hodgkin lymphoma Hodgkin lymphoma (HL) is a type of lymphoma, in which cancer originates from a specific type of white blood cell called lymphocytes, where multinucleated Reed–Sternberg cells (RS cells) are present in the patient's lymph nodes. The condition wa ...

. Howell–Jolly bodies are also seen in

amyloidosis Amyloidosis is a group of diseases in which abnormal proteins, known as amyloid fibrils, build up in tissue. There are several non-specific and vague signs and symptoms associated with amyloidosis. These include fatigue, peripheral edema, weight ...

, severe hemolytic anemia, megaloblastic anemia, hereditary spherocytosis, and myelodysplastic syndrome (MDS). The bodies can also can be seen in premature infants.

References

External links

Digital Pathology, Brown University: Howell-Jolly Bodies
{{DEFAULTSORT:Howell-Jolly body Abnormal clinical and laboratory findings for RBCs