Tear Drop Cells - Histology

What are Tear Drop Cells?

Tear drop cells, also known as dacrocytes, are abnormally shaped red blood cells that resemble a tear or a drop of water. These cells are often observed in peripheral blood smears and can provide valuable diagnostic information.

What Causes the Formation of Tear Drop Cells?

Tear drop cells can form due to various underlying conditions. One of the most common causes is myelofibrosis, a type of chronic leukemia that affects the bone marrow. Other conditions include thalassemia, megaloblastic anemia, and bone marrow infiltration by malignant cells. Mechanical damage as red blood cells pass through fibrotic tissue can also lead to their characteristic shape.

How are Tear Drop Cells Identified?

In histology, tear drop cells are identified through a peripheral blood smear stained with Wright-Giemsa stain. Under the microscope, they appear as red blood cells with a single pointed end, giving them a tear-like shape. The presence of these cells can be quantified and noted by a hematologist or a clinical pathologist.

What is the Clinical Significance of Tear Drop Cells?

The presence of tear drop cells in a blood smear often indicates an underlying pathological condition. In the case of myelofibrosis, tear drop cells are a hallmark finding and can help differentiate it from other hematologic disorders. Their presence in conditions like thalassemia and megaloblastic anemia also aids in the diagnosis and management of these diseases.

Can Tear Drop Cells be Reversed?

The reversibility of tear drop cells depends on the underlying cause. In conditions like megaloblastic anemia, appropriate treatment with vitamin B12 or folate can reduce the number of tear drop cells. However, in chronic conditions like myelofibrosis, the presence of these cells is usually persistent and may not be reversible.

Are Tear Drop Cells Specific to a Single Disease?

Tear drop cells are not specific to a single disease but are associated with a range of hematologic and systemic conditions. Their presence should prompt further diagnostic investigations to identify the underlying pathology. This often involves a combination of blood tests, bone marrow biopsy, and imaging studies.

What Other Cell Abnormalities are Seen with Tear Drop Cells?

Tear drop cells are often seen alongside other abnormal cells, depending on the underlying condition. For instance, in myelofibrosis, one might also observe leukoerythroblastosis (the presence of immature white and red blood cells) and nucleated red blood cells. In thalassemia, target cells and fragmented red blood cells may also be present.

How are Tear Drop Cells Reported in a Blood Smear?

When tear drop cells are identified in a blood smear, they are typically reported as part of a complete blood count (CBC) with differential. The report will note the percentage or absolute number of tear drop cells observed, along with other relevant findings such as anemia, reticulocytosis, and the presence of other abnormal cells.

What Histological Techniques are Used to Study Tear Drop Cells?

Histological examination of tear drop cells primarily involves peripheral blood smear analysis using stains like Wright-Giemsa. Advanced techniques such as flow cytometry and molecular studies may also be employed to investigate the underlying causes of their formation.

Conclusion

Tear drop cells are a significant histological finding that can indicate various underlying conditions, particularly those affecting the bone marrow. Their identification and analysis are crucial in diagnosing and managing hematologic disorders. Understanding the causes, clinical significance, and associated conditions of tear drop cells can provide valuable insights for both pathologists and clinicians in the field of hematology.