RBC Morphology Quiz

RBC Morphology

• Acanthocytes, or "spur cells," exhibit asymmetric projections and are associated with liver disease, Abetalipoproteinemia, and vitamin E deficiency.
• Echinocytes, known as "burr cells," have smaller, uniform projections and are linked to liver disease, end-stage renal disease (ESRD), and pyruvate kinase deficiency.
• Dacrocytes, or "teardrop cells," form when red blood cells (RBCs) are mechanically squeezed out of the bone marrow due to conditions such as myelofibrosis.
• Schistocytes, or "helmet cells," are fragmented RBCs associated with microangiopathic hemolytic anemias (MAHAs) like DIC, TTP/HUS, and HELLP syndrome, as well as mechanical hemolysis from heart valve prostheses.
• Degmacytes, or "bite cells," result from G6PD deficiency, where splenic macrophages remove Heinz bodies from the RBCs, giving them a "bite" appearance.
• Elliptocytes are found in hereditary elliptocytosis and are caused by mutations in genes that encode RBC membrane proteins, particularly spectrin.
• Spherocytes are identified in hereditary spherocytosis and autoimmune hemolytic anemia, characterized by their small size and spherical shape without central pallor, reflecting a decreased surface area-to-volume ratio.
• Macro-ovalocytes are commonly seen in megaloblastic anemia, alongside hypersegmented polymorphonuclear cells (PMNs).
• Target cells have an increased surface area-to-volume ratio and are associated with HbC disease, asplenia, liver disease, and thalassemia, summarized by the mnemonic "HALT."
• Sickle cells are characteristic of sickle cell anemia and emerge under low oxygen conditions (such as high altitude or acidosis) and with high concentrations of hemoglobin S (HbS), often related to dehydration.

RBC Inclusions

• Iron granules indicate sideroblastic anemias, including lead poisoning and myelodysplastic syndromes. They are seen as perinuclear mitochondria containing excess iron and require a Prussian blue stain for visualization.
• Howell-Jolly bodies appear in cases of functional hyposplenia (e.g., sickle cell disease) and asplenia. These are basophilic nuclear remnants, typically removed by splenic macrophages, and do not contain iron.
• Basophilic stippling consists of basophilic ribosomal precipitates observed in sideroblastic anemia and thalassemias; these stipplings do not contain iron.
• Pappenheimer bodies are basophilic granules that contain iron, often seen in sideroblastic anemia, analogous to "Pappen-hammer" bodies.
• Heinz bodies, related to G6PD deficiency, are denatured and precipitated hemoglobin that contain iron. They require a supravital stain (e.g., crystal violet) for detection and are removed by macrophages, resulting in bite cells.

RBC Morphology

• Acanthocytes (spur cells): Associated with liver disease, abetalipoproteinemia, and vitamin E deficiency; characterized by asymmetric projections of varying sizes at irregular intervals.
• Echinocytes (burr cells): Linked to liver disease, end-stage renal disease (ESRD), and pyruvate kinase deficiency; feature smaller, more uniform projections than acanthocytes.
• Dacrocytes (teardrop cells): Indicative of bone marrow infiltration, such as myelofibrosis; formed as RBCs are mechanically squeezed out of the bone marrow, resembling a tear.
• Schistocytes (helmet cells): Associated with microangiopathic hemolytic anemias (MAHAs) like DIC, TTP/HUS, and HELLP syndrome; fragmented red blood cells resulting from hemolysis.
• Degmacytes (bite cells): Common in G6PD deficiency; arise when splenic macrophages remove Heinz bodies, creating "bite" marks on the RBCs.
• Elliptocytes: Linked to hereditary elliptocytosis; caused by mutations in genes for RBC membrane proteins, leading to elongated RBC shapes.
• Spherocytes: Found in hereditary spherocytosis and autoimmune hemolytic anemia; small and spherical with decreased surface area-to-volume ratio, lacking central pallor.
• Macro-ovalocytes: Typically seen in megaloblastic anemia; often accompanied by hypersegmented neutrophils.
• Target cells: Associated with HbC disease, asplenia, liver disease, and thalassemia; characterized by increased surface area-to-volume ratio, resembling a target.
• Sickle cells: Present in sickle cell anemia; sickling occurs under low oxygen conditions or high HbS concentration, leading to distorted shapes.

RBC Inclusions

• Iron Granules: Found in sideroblastic anemias due to lead poisoning, myelodysplastic syndromes, or chronic alcohol overuse; perinuclear mitochondria contain excess iron, requiring Prussian blue stain for visualization.
• Howell-Jolly Bodies: Indicative of functional hyposplenia or asplenia, prevalent in sickle cell disease; consist of basophilic nuclear remnants typically removed by splenic macrophages.
• Basophilic Stippling: Associated with sideroblastic anemia and thalassemias; represents ribosomal precipitates that don’t contain iron.
• Pappenheimer Bodies: Found in sideroblastic anemia; characterized by basophilic granules containing iron.
• Heinz Bodies: Present in G6PD deficiency; consist of denatured and precipitated hemoglobin with iron, requiring a supravital stain such as crystal violet for visualization.

RBC Morphology

• Acanthocytes ("spur cells"): Associated with liver disease, Abetalipoproteinemia, and Vitamin E deficiency. Characterized by asymmetric projections of varying sizes along the RBC membrane.

• Echinocytes ("burr cells"): Occur in liver disease, end-stage renal disease (ESRD), and pyruvate kinase deficiency. Feature smaller, uniformly spaced projections on the cell surface.

• Dacrocytes ("teardrop cells"): Indicative of bone marrow infiltration, such as myelofibrosis. Appear as if the RBC is "shedding a tear" due to mechanical squeezing when leaving the bone marrow.

• Schistocytes ("helmet cells"): Found in microangiopathic hemolytic anemias (MAHAs) like DIC, TTP/HUS, and HELLP syndrome, as well as in mechanical hemolysis. Fragmented RBCs that indicate severe hemolysis.

• Degmacytes ("bite cells"): Associated with G6PD deficiency, formed when splenic macrophages remove Heinz bodies from RBCs, leading to a "bite" appearance.

• Elliptocytes: Present in hereditary elliptocytosis, caused by mutations in genes affecting RBC membrane proteins such as spectrin.

• Spherocytes: Linked to hereditary spherocytosis and autoimmune hemolytic anemia. Feature a spherical shape lacking central pallor, resulting in a reduced surface area-to-volume ratio.

• Macro-ovalocytes: Typically found in megaloblastic anemia, accompanied by hypersegmented polymorphonuclear leukocytes (PMNs).

• Target cells: Associated with conditions like HbC disease, asplenia, liver disease, and thalassemia. Exhibit increased surface area-to-volume ratio; commonly remembered by the mnemonic "HALT."

• Sickle cells: Present in sickle cell anemia, characterized by sickling patterns under low oxygen conditions, such as high altitude or acidosis, and when HbS concentration is elevated.

RBC Inclusions

• Iron Granules: Seen in sideroblastic anemias, including lead poisoning and myelodysplastic syndromes. Characterized by perinuclear mitochondria filled with excess iron, sometimes forming rings in ringed sideroblasts; requires Prussian blue stain for visualization.

• Howell-Jolly Bodies: Found in functional hyposplenism (e.g., sickle cell disease) and asplenia. These are basophilic remnants of nuclear material that typically get removed by splenic macrophages.

• Basophilic Stippling: Associated with sideroblastic anemia and thalassemias. Composed of basophilic ribosomal precipitates that do not contain iron.

• Pappenheimer Bodies: Present in sideroblastic anemia, appearing as basophilic granules containing iron, commonly known as "Pappen-hammer" bodies.

• Heinz Bodies: Linked to G6PD deficiency, formed by denatured hemoglobin that precipitates. They are phagocytosed by macrophages leading to the formation of bite cells, requiring a supravital stain such as crystal violet for visualization.

RBC Morphology

• Acanthocytes (spur cells): Associated with liver disease, abetalipoproteinemia, and vitamin E deficiency; characterized by asymmetrical projections of varying sizes along the membrane.
• Echinocytes (burr cells): Linked to liver disease, end-stage renal disease (ESRD), and pyruvate kinase deficiency; feature smaller, more uniform projections compared to acanthocytes.
• Dacrocytes (teardrop cells): Indicative of bone marrow infiltration, such as myelofibrosis; shaped like teardrops due to mechanical squeezing during release from the bone marrow.
• Schistocytes (helmet cells): Associated with microangiopathic hemolytic anemias (MAHAs) including DIC, TTP/HUS, and HELLP syndrome; appear as fragmented red blood cells.
• Degmacytes (bite cells): Seen in G6PD deficiency; form when splenic macrophages remove Heinz bodies from RBCs, creating a "bite" appearance.
• Elliptocytes: Found in hereditary elliptocytosis; arise from mutations in genes responsible for red blood cell membrane proteins, such as spectrin.
• Spherocytes: Observed in hereditary spherocytosis and autoimmune hemolytic anemia; small, round cells lacking central pallor, resulting in a decreased surface area-to-volume ratio.
• Macro-ovalocytes: Common in megaloblastic anemia; often accompany hypersegmented neutrophils.
• Target cells: Associated with hemoglobin C disease, asplenia, liver disease, and thalassemia; characterized by an increased surface area-to-volume ratio, resembling a target.
• Sickle cells: Seen in sickle cell anemia; deformities occur under low oxygen tension, such as high altitude or acidosis, and higher hemoglobin S concentrations due to dehydration.

RBC Inclusions

• Iron Granules: Associated with sideroblastic anemias, including lead poisoning and myelodysplastic syndromes; found in perinuclear mitochondria as excess iron, often identified with Prussian blue stain.
• Howell-Jolly Bodies: Indicative of functional hyposplenia or asplenia; consist of basophilic nuclear remnants, typically removed by splenic macrophages, and do not contain iron.
• Basophilic Stippling: Present in sideroblastic anemia and thalassemias; characterized by basophilic ribosomal precipitates that lack iron.
• Pappenheimer Bodies: Found in sideroblastic anemia; consist of basophilic granules that contain iron, sometimes colloquially referred to as "Pappen-hammer" bodies.
• Heinz Bodies: Associated with G6PD deficiency; consist of denatured and precipitated hemoglobin, requiring supravital stain (like crystal violet) for visualization, as they are removed by macrophages leading to bite cells.