What is the characteristic abnormal red blood cell morphology in myelofibrosis?

In myelofibrosis, the characteristic abnormal red blood cell morphology is the presence of teardrop cells. This condition often involves disruption of normal hematopoiesis due to fibrosis of the bone marrow, leading to altered red blood cell shapes as they leave the marrow. Teardrop cells, or dacrocytes, arise as red blood cells are forced through the fibrotic, constricted environment of the marrow, resulting in their distinctive elongated, pointed shape. The presence of these cells is indicative of myelofibrosis and reflects the underlying pathology associated with the disease.

Other types of abnormal red blood cells, like target cells, schistocytes, and ovalocytes, can be seen in different hematological disorders but are not specific to myelofibrosis. Target cells are commonly seen in conditions like liver disease or thalassemia, schistocytes often appear in conditions of hemolysis or microangiopathic processes, and ovalocytes are associated with disorders such as hereditary ovalocytosis or iron deficiency anemia.