The blood smear of a patient shows the following as represented in the picture below. Identify the structure marked as “A and B”?
A. A-Cabot ring
B. A-Howell-Jolly body
C. A-Cabot ring
D. A-Spurr cells
- They are histopathological findings of basophilic nuclear remnants (clusters of DNA) in circulating erythrocytes.
- During maturation in the bone marrow 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.
- Howell–Jolly bodies are also seen in: amyloidosis, severe hemolytic anemia, megaloblastic anemia, hereditary spherocytosis, heterotaxy with asplenia and myelodysplastic syndrome (MDS).
- Also can be seen in premature infants.
- They are thin, red-violet staining, threadlike strands in the shape of a loop or figure-8 that are found on rare occasions in red blood cells (erythrocytes).
- They are believed to be microtubules that are remnants from a mitotic spindle, and their presence indicates an abnormality in the production of red blood cells.
- Cabot rings have been observed in megaloblastic anemia, lead poisoning, severe anemia, leukemia, myelodysplastic syndromes, and other cases of dyserythropoiesis.