Interpretation of Abnormal Blood Smear Findings

Introduction to Abnormal Findings

The European Society for Medical Oncology (ESMO) recognizes red cell morphology abnormalities, such as polychromasia, hypochromasia, target cells, and teardrop cells, as signs of dysplasia in myelodysplastic syndromes (MDS) 2, 4
Persistent platelet clumping across multiple specimens may indicate an underlying platelet disorder requiring further investigation 1

Polychromasia indicates the presence of young red blood cells (reticulocytes) in peripheral blood, suggesting increased erythropoiesis in response to anemia or blood loss 2, 3
Hypochromasia is characterized by decreased hemoglobin content in red cells, resulting in increased central pallor, and is commonly seen in iron deficiency anemia, thalassemia, and sideroblastic anemia 2, 3
Target cells are associated with liver disease, hemoglobinopathies, post-splenectomy states, and some membrane disorders 2, 4
Teardrop cells are pear-shaped red cells that may indicate bone marrow infiltrative disorders and are strongly associated with myelofibrosis, myelodysplastic syndromes, and other myeloproliferative neoplasms 2, 4

The combination of red cell morphology abnormalities, particularly when persistent across multiple specimens, warrants consideration of myelodysplastic syndromes (MDS) 2, 4
The American Heart Association, as published in Circulation, notes that patients with cyanotic heart disease may develop hypochromic red cells due to iron deficiency, which can further compromise oxygen delivery 3
If clinical suspicion for MDS exists, bone marrow aspiration and biopsy with cytogenetic studies should be considered, as recommended by the European Society for Medical Oncology (ESMO) 2, 4
Flow cytometry to evaluate platelet glycoproteins may be considered if a platelet function disorder is suspected, according to the International Society on Thrombosis and Haemostasis 5, 6