| The cell diameter of a normal RBC is slightly smaller than the nucleus of a small lymph. | View Page |
| Erythrocyte Shape In stained blood films, only the flattened surfaces of the RBC's are seen. Therefore, they appear circular with an area of central pallor corresponding to the indented area. The central pallor occupies about 1/3 of the diameter of the cell. | View Page |
| Function and Kinetics Erythrocytes are produced in the bone marrow and released into the peripheral blood where they may remain for approximately 120 days before senescence.Their main function is the transport of the respiratory gases (oxygen and carbon dioxide) between the lungs and body tissues.Each erythrocyte can be thought of as an "envelope" containing hemoglobin.Each hemoglobin molecule contains iron which has a high affinity for oxygen.As a result, when an erythrocyte passes through one of the capillaries of the lungs, it picks up oxygen.The oxygen is transported through the blood to the tissues where it is released.Carbon dioxide from the tissues then diffuses into the RBC where it undergoes chemical changes.About 70% of the altered carbon dioxide diffuses into the plasma, 25% binds to the hemoglobin molecule, and 5% goes into simple solution within the red cell.In each of these three ways carbon dioxide is transported from the body tissues back to the lungs, where it is released.
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| All of the following methods can be used to transport carbon dioxide to the lungs EXCEPT: | View Page |
| Erythrocytes or Red Blood Cells (RBC's) The first group is composed of erythrocytes or red blood cells (RBC's). The main function of the erythrocytes is the transport of oxygen from the lungs to the body tissues. Most of the cells in this Wright's stained peripheral blood smear are red cells. On is shown at the arrowhead. | View Page |
| Glossary of Terms A through M. Antibody - A modified type of serum globulin synthesized by lymphoid tissue in response to antigenic stimulus. By virtue of specific combining sites each antibody reacts with only one antigen. Anucleate - Having no nucleus. Azurophilic granules - The well-defined large reddish granules (lysosomes) which may be present in large lymphocytes. They are called "azurophilic granules" because they stain blue with the azure stains which were originally used. Basophilic granules - Specific granules present in the cytoplasm of basophils. These granules are large and stain purple-black due to their strong affinity for basic stain. B-cell - Bone marrow derived lymphocytes which produce humoral antibodies. Biconcave - Having two concave surfaces. Cellular Immunity - The capacity of a small proportion of lymphoid population to exhibit response to a specific antigen. Chromomere - The centrally located granular portion of the platelet. Clone - A population of cells descended from a single cell. Delayed Hypersensitivity - (part of cellular immunity) that develops slowly over a period of 24-72 hours after an antigenic stimulus. It consists of an accumulation of cells around small vessels and/or nerves. Example: Tuberculin skin test reaction. Digestive Enzyme - A substance that catalyzes or accelerates the process of digestion. Eosinophilic Granules - Specific granules present in the cytoplasm of eosinophils. These granules are large, refractile spheres which stain reddish-orange due to their strong affinity for acid stain. Erythrocyte (red blood cell, RBC) - One of the elements found in peripheral blood. Normally the mature form is a non-nucleated, circular, biconcave disk adapted to transport respiratory gases. Fixed Macrophage - A phagocyte that is non-motile. Free Macrophage - An ameboid phagocyte present at the site of inflammation. Graft Rejection - A transplanted tissue that is rejected by the body's antibodies. Graft vs. Host Reaction - A complication that occurs when an implanted piece of tissue, which contains antibodies, rejects the host's tissue. Granulocyte - A leukocyte which contains granules in its cytoplasm, i.e., neutrophilic, eosinophilic, or basophilic granules. Half-life - is the length of time it takes for half of the cells circulating at a given time to leave the blood for the tissues. Hemocyte - Any blood cell or formed element of the blood. Hemostasis - A mechanism of the vascular system to arrest an escape of blood. It involves an interaction between blood vessels, platelets, and coagulation. Heparin - A mucopolysaccharide acid which, when present in sufficient amounts, functions as an anticoagulant by inhibiting thrombin. Histamine - A powerful dilator of capillaries and a stimulator of gastric secretions. Humoral Immunity - Acquired immunity produced after response to an antigenic stimulus in which B cells produce circulating antibodies. Hyalomere - the clear, blue non-granular zone surrounding the chromomere of a platelet. Immune Response - The interaction of a cell and an antigen that results in a proliferation of the cell and a capacity to produce antibodies. Isotonic Fluid - A fluid whose elements have an equal osmotic pressure. Leukocyte (white blood cell, WBC) - One of the formed elements of the blood; involved primarily with the body's defense. Lysosome - A microscopic body within cell cytoplasm; contains various enzymes, mainly hydrolytic, which are released upon injury to the cell. Megakaryocyte - A giant cell of the bone marrow from which platelets are derived. Mononuclear - A cell having a single nucleus. | View Page |
| Nucleus of Lymphocyte The nucleus is slightly larger than a normal RBC. It is usually round or oval in shape, but may be slightly indented. The chromatin is very dense and clumped.
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| Note the view of a peripheral blood smear in the photograph. Pictured are scattered acanthocytes, echinocytes, target cells, spherocytes, and schistocytes. The condition in which each of these atypical RBC's may be found in varying numbers in the same peripheral blood smear is: | View Page |
| The peripheral blood picture shown in the photograph is most consistent with an artifact of smear preparation. | View Page |
| Pappenheimer bodies Pappenheimer bodies are iron-containing granules that aggregate with mitochondria and are deposited in RBC or normoblast cytoplasm. Small and irregular, they are found only in pathological states as thalassemia and sideroblastic anemias(upper image). Wright-Giemsa stain defines the cytoplasmic content (protein), but Prussian blue staining is necessary to define the iron content, the essence of the Pappenheimer body (lower image). Pappenheimer bodies lie typically in small clusters (upper image) and tend to locate at the periphery of the red cell cytoplasm. A cluster is typically smaller than a single Howell-Jolly body. | View Page |
| The RBC inclusions shown in the photograph represent which of the following? | View Page |
| The peripheral blood smear represented by this field was submitted for hematologic review. The RBC inclusions most likely are: | View Page |
| Intracellular RBC Inclusions-G6PD (continued) G6PD deficiency occurs in the same geographic distribution as malaria. It has been theorized that enzyme deficient cells are more resistant to malarial parasites than normal cells.When hemolysis is triggered, the appearance of the red blood cells is modulated by activity of the spleen.Spherocytes, schistocytes, and nucleated red blood cells may appear in the peripheral blood.Denatured hemoglobin removed by an active spleen may leave bite cells, identified by the arrows in this photomicrograph, suggesting the presence of G6PD deficiency. | View Page |
| Leukoerythroblastosis Illustrated in this field is a normoblast and a myelocyte, representing leukoerythroblastosis, a term associated with the release of immature cells from a disrupted marrow. Metastatic disease in the bone marrow, particularly in patients with primary breast or prostate cancer, is usually the culprit. Leukoerythroblastosis in the absence of anemia or thrombocytopenia is a signal to search for cancer metastic to the marrow. Nucleated RBCs were not identified on the blood smear seen here but were detected by an automated analyzer.The mortality rate of elderly patients with increased NRBCs, especially following accidents or general surgery, is greater. | View Page |
| DIC: graft vs. host disease The peripheral smear illustrated in the photograph was obtained from a patient with a recent renal transplant. The patient developed a rash, accompanied by nausea and diarrhea. Graft vs. host disease was clinically suspected. The peripheral smear findings are consistent with that diagnosis. The presence of spherocytes suggests a hemolytic process which is supported by the presence of nucleated RBCs. A few scattered schistocytes and the decrease of platelets suggests DIC. The presence of target cells presents the possibility of associated liver disease. Additional tests, particularly coagulation studies, should confirm the diagnosis of microangiopathic hemolytic anemia. | View Page |
| Cardiac hemolysis (Waring Blender Effect) Two photographs of a peripheral blood smear are submitted for review . The smears are from a 9-month-old baby with a heart valve replacement. In the upper photograph is a nucleated RBC and platelets are decreased. Nucleated red cells and occasional giant platelets indicate an active marrow response. In the process of forcing blood cells through the heart valve, erythrocytes are damaged, schistocytes are formed, and platelets are destroyed leading to thrombocytopenia. In the lower field are schistocytes, acanthocytes, echinocytes (burr cells), spherocytes, and the absence of platelets. The presence of burr cells could represent an artifact of smear preparation, but with the history of valve replacement, the red cell changes are likely the result of red cell damage as the cells circulate through the new valve. This situation is described as Waring Blender Effect because of damage to blood cells passing through the new valve, looking as if they had suffered the onslaught of a blender. Target cells and mild hypochromia may reflect iron deficiency through the loss of iron from destruction of RBC's. Iron loss through red cell destruction may be reflected in some hypochromia. | View Page |
| The presence of erythrocytes with altered morphology (as photographed here) has a close association with each of the following conditions except: | View Page |
| The underlying condition where the defective erythrocytes marked by arrows are of diagnostic importance is: | View Page |
| Atypical smear: Case follow-up The patient whose blood smear is shown in the photograph was a 32-year-old female from Virginia who came to the high country of Colorado to ski. The day after arrival, she experienced shortness of breath, fatigue, and upper abdominal pain. She was seen in a medical center in the mountains where a working diagnosis of altitude sickness was made. A CBC revealed RBCs 5.1 x 1012/L, hemoglobin 12.8g/dL, MCV 60fL, hematocrit 40.9%, and normal total WBC, differential, and platelet count. The RDW was normal. Further questioning revealed a previous diagnosis of heterozygous beta-chain thalassemia. No other abnormal hemoglobins were found on hemoglobin electrophoresis, but HbA-2 was elevated to 5%, supporting the diagnosis of beta thalassemia. The patient's poikylocytosis and anisocytosis may be a clue to an underlying erythrocyte abnormality. Persons with iron deficiency anemia may experience various degrees of hypoxia upon arriving at high altitudes. Those with sickle cell disease and thalassemia minor (as in this case) may experience bone pain or other symptoms of "crisis" and/or alteration in the appearance of their erythrocytes upon sudden high altitude exposure. The classic teaching is that in differentiating iron deficiency anemia from thalassemia, increased RDW would favor iron deficiency; normal RDW favors thalassemia. | View Page |
| The photograph is representative of the peripheral blood smear of a five-month-old immigrant from Asia. Her mother was concerned that the child was not eating well. Her spleen was palpable.The hemogram revealed the following:Hb 9.6g/dL (normal 12.0 - 16.0 g/dL)RBC 5.48 X 1012/L (normal 4.2 - 5.9 X 1012/LHCT 30.4% (normal 37 - 48%)MCV 55.4 fl (normal 86 - 98 fl)MCH 17.5 pg (normal 27 - 32 pg)MCHC 31.6 g/dL (normal 31 - 37 g/dL)RDW 34.9% (normal 11 - 15%)Reticulocyte count 10.9% (normal 0.5 - 1.5%)Select the most likely diagnosis based on the clinical information and peripheral blood findings. | View Page |
| Hb E disease (continued) The family (cited in the previous case history) was from a region of Thailand where the physician knew HbE carriers are prevalent. Homozygous hemoglobin E is common in Southeast Asia and presents with very mild anemia and seldom requires transfusion. Over 30 million people in the world are HbE carriers, making this abnormal hemoglobin almost as common as HbS. Hemoglobin E is uncommon in North America and in Europe, but with changing immigration patterns, hemoglobinopathy E cannot be ignored. Peripheral blood smear findings of target cells, microspherocytes, red cell hypochromia, a few red blood cell fragments, and nucleated red blood cells require evidence from hemoglobin electrophoresis to establish a diagnosis. Clinically, a very important and severe syndrome is hemoglobin E/beta thalassemia in which there is hemolysis requiring repeated transfusions. The patient has a severe anemia, low MCV (50's), and high RBC. This is characteristic of Hgb E/beta thalassemia. | View Page |
| Rouleaux Rouleaux formation correlates with an increased concentration of serum monoclonal proteins. Rouleaux may be seen as an artifact in the thicker portions of blood smears. The addition of a drop of saline to the blood smear will serve to disperse any artifactual rouleaux formation. The presence of rouleaux formation or RBC agglutination may result in a falsely decreased electronic red blood count and falsely increased MCV, as these clusters may be read as one cell. | View Page |
| The arrangement of erythrocytes on this peripheral blood smear may be seen in each of the following conditions except: | View Page |
| The arrangement of the erythrocytes in this peripheral smear should be reported out as rouleaux formation. | View Page |
| Dimorphic RBC population Illustrated in the photomicrograph of a peripheral smear are two populations of erythrocytes. Approximately 50% of the erythrocytes are normal size and contain a full complement of hemoglobin. The patient had received blood transfusions. The transfused red blood cells are the normocytic, normochromic red cells. Admixed are microcytic erythrocytes and larger erythrocytes, some faintly mottled or smudged, suggestive of reticulocytes. This picture represents a hemolytic process with a reticulocyte response. A similar dimorphic red cell population appears following erythropoietin therapy. It is important to recognize when a population of cells in the peripheral smear is not in context with anticipated laboratory findings and the clinical situation. | View Page |
| Stomatocytes Stomatocytes are erythrocytes with a slit-like central pallor. Otherwise, they resemble typical RBC's in size and shape. Unless 10% or more of the RBC's are stomatocytes, their presence is probably artifactual. Stomatocytes form at a low blood acidic pH as seen in exposure to cationic detergents, and in patients receiving phenolthiazine. Hereditary stomatocytosis has some resemblance to hereditary spherocytosis, as stomatocytes may develop into spherocytes with further metamorphosis. In hereditary stomatocytosis, mild anemia and findings of on-going hemolysis should be evident if the condition presents as a clinical problem at all. | View Page |
| Criteria for peripheral blood smear review Initial analysis of the peripheral blood picture is made in most clinical laboratories with an automated instrument. Samples are selected for further analysis when quantitative or qualitative abnormalities beyond a defined standard are found. The following are examples of quantitative RBC abnormalities that may prompt a blood smear review. Each laboratory, however, should develop its own guidelines: Hgb: < 8 or >18 g/dL (<10 or > 21g/dL in a newborn)Hct: <20% or > 60% in adults (<40% or >65% in a newborn)MCHC: <29 g/dLMCV: <69 femtoliters (fl) or >110flFlags generated by the hematology analyzer that indicate possible red cell abnormalities or spurious resultsAny of these findings should be followed up with a peripheral blood smear review. | View Page |
| Guidelines for standard reports In a study on the reporting of red blood cell morphology abnormalities conducted in Ontario, Canada (Hookey L, Dexter D, Lee DH, Laboratory Hematology 7:83-88, 2001), fewer than 50% of 33 participants used the same term to describe the quantitative frequency of peripheral blood abnormalities. Seven blood smears, each containing one of several abnormal erythrocytes-- schistocytes, teardrop cells, acanthocytes, and Howell-Jolly bodies--were evaluated by 32 participants. The participants were asked to document their evaluations from a list of quantitative terms. There was a heterogeneity in the use of terms "rare," "slight," "occasional," "few," "mild", "present," "moderate," "many," and "marked." Choices of terms were subjective without points of reference. Guidelines for establishing standardized qualitative estimations of abnormal erythrocytes in the peripheral smear are presented as follows: 1+ = 2 - 4/Oil Immersion Field (OIF) 2+ = 5 - 7/OIF 3+ = 8 - 10/OIF 4+ = >10/OIF. The terms "few," "moderate," "many," and "marked" may be substituted for the 1+ - 4+ grading system, but only when their specific points of reference are universally understood in tandem with the above guidelines. A comment should be triggered if any erythrocyte abnormalities are seen in numbers >3/OIF including, but not limited to, polychromasia, basophilic stippling, nucleated RBC's, and Howell-Jolly bodies. Rouleaux or RBC agglutination are important findings and must be documented. | View Page |
| The patient was a female and the examination was completed within two hours of collection. Which of the following findings correlate with the presence of a yeast infection of the bladder? | View Page |
| What element is present in this slide? | View Page |
| True or false? RBCs are present in this slide. | View Page |
| True or false? WBCs are present in this slide. | View Page |
| Match the following: | View Page |
| Red Cell Casts Red cell casts appear as clear cylinders containing red blood cells and may have an orange red tinge. Their presence indicates bleeding into the nephron.
Red cells within the cast are rapidly hemolyzed and the cast becomes a hemoglobin cast, having an orange color and a homogeneous ground-glass texture. In order for a cast to be considered an RBC cast, the outline of the red cells must be clearly visible in at least one area of the cast. | View Page |
| Red and White Cells There are many red and white cells in this high power field. There are a group of five red cells that can be identified on the lower right-hand side of the field. It is important to use the fine focus adjustment on the microscope when trying to differentiate RBCs from WBCs. | View Page |
| Swollen RBCs In contrast, RBCs appear swollen in dilute or alkaline urine, having taken on water from their surroundings. | View Page |
| Yeast Yeast can appear as single cells or in the budding form. As single cells they can be confused with RBCs because they are about the same size. In the budding form, yeast is easily identified as demonstrated on this slide. Yeast can be found in patients with cystitis due to yeast, usually candida, or as a vaginal contaminant from patient's with vaginal candidiasis. | View Page |
| Which of the following are characteristic of normal RBCs under high power (40x) brightfield microscopy? | View Page |
| All of the following are characteristic of WBCs under high power (40x) brightfield microscopy except that they: | View Page |
| Cells Types Observed in Urine Sediment Cells which may be present in the urine include epithelial cells, white blood cells (WBC) and red blood cells (RBC). The epithelial cells in the urine may originate from any site in the genitourinary tract. It is normal to find a few epithelial cells in the sediment. White blood cells may enter the urinary tract anywhere from the glomerulus to the urethra. The WBCs are mostly neutrophils. Red blood cells may originate in any part of the urinary tract. Normally, RBCs do not appear in the urine, although the presence of a few RBCs is not considered abnormal. | View Page |
| Red Blood Cells Red blood cells (RBCs) may also be found in the urine sediment. The presence of RBCs in the sediment is associated with damage to the glomerular membrane or vascular injury within the genitourinary tract (the possibility of menstrual contamination must be considered). | View Page |
| In concentrated urine RBCs may appear: | View Page |
| Specimen #4 - Adult Male The results of this specimen are abnormal but the abnormalities correlate with each other. The turbidity can be explained by the presence of bacteria and crystals. The presence of RBCs in the microscopic explains the blood found on the dipstick. The casts, bacteria and WBCs can account for the increased protein. The results may be reported. | View Page |
| Match the following.Note: Answers may be used more than once. | View Page |
| Counting Elements Next the number of RBCs, WBCs, epithelial cells, parasites, and fat will be counted. Move to the center of the coverslip and examine 10 fields under high power (40x) brightfield. Use phase-contrast as needed. Determine the average number of each element found and record the findings as number per high power field (#/HPF). An abundance of any one element may be recorded as >100/HPF when 1/4 field is counted and the total field is estimated to be greater than 200/HPF. | View Page |
| The cells included in the composite image were found in a peripheral blood smear with a total WBC of 24,500/mm3. The differential count was:
myelocytes 1
metamyelocytes 4
band neutrophils 15
segmented neutrophils 40
monocytes 8
eosinophils 2
basophils 1
lymphocytes 29.
This hematologic picture is most consistent with: | View Page |
| The upper photograph of a peripheral blood smear reveals RBC rouleaux formation. Nucleated cells evident in both upper and lower photographs comprise approximately 5% of the total white blood cell count. The most probable underlying condition is: | View Page |
| The peripheral blood smear tagged in the photograph was held for review because of too many platelets, about double the normal average of 8 - 15/oil immersion field or one per 10 - 20 RBC's. Conditions in which platelets are increased as noted in the photograph include: | View Page |
| A peripheral blood smear is submitted for morphology review. The patient is a 10 year-old boy with symptoms suggesting appendicitis and an appendectomy is being considered. The total WBC is 18.5 X 1000/uL, RBC's = 5.45 X 1M/uL, hemoglobin = 16.0 g/dL, hematocrit 48.2%;wbc differential: Segs = 53%, bands = 42% (two of which are shown in the photograph), monocytes = 2%, and lymphocytes= 2%. These findings support the diagnosis of appendicitis. | View Page |
| Case History 2 An 80 year old man was seen in the emergency room with sudden onset of right sided chest pain accentuated on inspiration. His cough was productive of yellow sputum, and he was short of breath.His temperature was 101.2F. A chest X-ray revealed right middle lobe pneumonia. His hemoglobin was 15.2 gm/dl, HCT 44%, and RBC 4.5 m/ml. The white blood count was 35,000/cuml, with 45% neutrophils, 20% bands, 5% lymphocytes, 3% eosinophils, 2% basophils, and 25% atypical monocytes as noted in the photograph.The atypical monocytes had abundant blue-grey cytoplasm with a few scattered vacuoles, which, in company with toxic neutrophils appeared to be a response to infection.The patient had a past history of tuberculosis which may account for the monocytosis. | View Page |