What Can You Learn From A Stream Morphology Lab

Blood morphology adds profoundly to the value of a routine blood count. A skillful exam of a well-made blood smear constitutes the about valuable unmarried procedure in the hematology laboratory. In spite of normal blood count figures, conscientious observation of blood morphology suggested previously unsuspected disorders. For example, in some cases, the finding of hypersegmented neutrophils on the blood smear was the starting time hematologic clue to a meaning deficiency of vitamin B12 or folate, the erythrocytes lacking the characteristic macrocytosis associated with such deficiencies.

Hypersegmented Neutrophil

The reporting of blood morphology has been improving in contempo years, although in many clinical laboratories, information technology withal receives little attending. The claret count study course ofttimes leaves only a tiny area for morphologic comments!

A blood smear is a drop of blood spread thinly onto a drinking glass slide that is and then treated with a special stain and examined under a microscope by a trained laboratorian. Information technology is a snapshot of the cells that are nowadays in the fluid portion of the blood (plasma) at the fourth dimension the sample is obtained.  The results of a claret smear typically include a description of the advent of the crimson blood cells, white blood cells, and platelets too as whatsoever abnormalities that may be seen on the slide.

Red Blood Cell Morphology

Cherry-red blood cells (erythrocytes) are biconcave disks with a diameter of seven-8 microns, which is like to the size of the nucleus of a resting lymphocyte.  In normal red blood cells, at that place is an area of key pallor that measures approximately ane/3 the diameter of the jail cell.  Though reference ranges vary between laboratories and in different age groups, normocytic red blood cells typically have a mean corpuscular volume (MCV) betwixt fourscore-100 fL.

Normal RBCs

Spherocytes are formed when there is a loss of office of the carmine blood cell membrane.  This may occur in the setting of immune-mediated hemolysis or congenital red jail cell membrane defects such equally hereditary spherocytosis.  Spherocytes are smaller than normal red claret cells and lack central pallor.  They are less deformable and less able to navigate through small vessels, leading to increased destruction in the spleen.

Spherocytes – Hereditary Spherocytosis

Microcytic red claret cells measure vi microns or less in diameter.  The mean corpuscular volume is generally less than eighty fL, though the normal range varies slightly between laboratories and in different age groups.  In contrast to spherocytes, which are as well decreased in diameter, microcytes retain their central pallor.  In microcytosis due to iron deficiency, the central pallor is increased (more than 1/iii the diameter of the cell).

Microcytosis with lymphocyte for comparing

Teardrop cells in a peripheral blood smear from a patient whose bone marrow was extensively replaced past B lymphoblastic leukemia.  Teardrop cells may be seen in the setting of marrow infiltration (by fibrosis, granulomatous inflammation, hematologic or metastatic malignancy), splenic abnormalities, megaloblastic anemia, and thalassemia.  True teardrop cells take slightly rounded or blunted ends.  In dissimilarity, teardrop cells that are formed as an artifact of smear preparation have very sharp points, all facing in the same direction.

Teardrop Cells (Dacrocytes)

Cabot rings are thin, threadlike, cherry-red to violet rings or "figure eight" shaped inclusions in red blood cells.  Cabot rings are remnants of the mitotic spindle, and tin can exist seen in megaloblastic anemia, medication issue, myelodysplasia and other forms of dyserythropoiesis.  In this image of a blood smear from a patient with vitamin B12 deficiency, the Cabot ring is visible equally a faint ring-shaped inclusion in the polychromatophilic cell in the center of the field.

Cabot Band

Peripheral blood smear of a 38-twelvemonth-old female person with long-standing Crohn's disease (CD) and development of microcytic anemia. The smear shows numerous target cells and a spur cell(elevation correct). All liver office tests were aberrant indicating that the target cells are due to liver affliction secondary to CD. This patient originally had a concomitant atomic number 26 deficiency. Spur red cells take elongated projections while Burr cells are red cells with circumferential blunted borders. The erstwhile is typically seen in liver disease while the latter is seen in uremia. The "Burr" morphology, in this example, is artifactual related to slide preparation and not related to uremia.

Target and Spur prison cell in liver illness

Acanthocytes in two patients with liver disease. Acanthocytes (also chosen spur cells) are spiculated cells with irregular, pointed or clublike projections that are unevenly distributed on the jail cell surface.  Central pallor is absent.  Acanthocytes form as a consequence of membrane lipid abnormalities, and can be seen in liver affliction, neuroacanthocytosis, severe malnutrition, and abetalipoproteinemia.

Acanthocytes (Spur Cells)

Sickle cells (drepanocytes) are elongated red blood cells with pointed ends.  They are seen in sickling hemoglobinopathies such as sickle cell anemia (homozygous hemoglobin SS), hemoglobin SD disease, and hemoglobin Due south/beta-thalassemia.

Sickle Cells

Echinocytes (Burr Cells) take multiple short, blunt projections evenly spaced over the jail cell surface.  The fundamental pallor is retained.  Echinocytes can be seen in uremic patients.  They tin can also be seen equally an artifact of slide grooming or prolonged specimen storage.

Burr Cells or Echinocytes

Stomatocytes are red cells with a slit-like or "fish-oral cavity" fundamental pallor. Stomatocytes may be seen in patients with alcoholic liver disease, hereditary stomatocytosis, or Rh null disease, among other conditions.  They may formin vitroin the presence of sure cationic medications or depression pH.

Stomatocytes

Red cell fragments (schistocytes) in a patient with microangiopathic hemolysis due to thrombotic thrombocytopenic purpura (TTP).  Small triangulocytes and larger, crescent-shaped helmet cells are present.  Both of these are red prison cell fragments and would be included in the schistocyte count.  When numerous small schistocytes are present, automated prison cell counters may count the small crimson cell fragments every bit platelets, leading to a falsely elevated automated platelet count.

Schistocytes – triangulocytes and helmet cells

Oxidative hemolysis induced by furosemide in a patient with G6PD deficiency.   In oxidative hemolysis, the peripheral smear may bear witness irregularly contracted cherry blood cells, hemighost or cicatrice cells, and spherocytes.  Irregularly contracted cells lack central pallor, and the hemoglobin appears condensed and irregularly distributed in the ruby-red blood cell.

Irregularly contracted cells in oxidative hemolysis

Clumping (agglutination) of ruby claret cells is often acquired by cold agglutinins.  Cold agglutinins are IgM antibodies that may ascend following viral or Mycoplasma infections, or in the setting of plasma jail cell or lymphoid neoplasms.  Agglutination of crimson cells tin interfere with cerise blood cell indices.  The red claret cell count may be falsely decreased, and the MCV falsely increased, as clumps of cherry-red cells are measured as single cells.  The hemoglobin level will be accurate, as this parameter is measured after lysing the ruby-red cells.

Polychromasia (polychromatophilic cells) in a neonate.  Polychromatophilic cells are young cherry-red blood cells that accept been recently released from the bone marrow.  They are larger than mature red cells, and are bluish in color.  Polychromasia is increased in hemolysis, blood loss, and marrow infiltration.  Normal neonates have a higher number of polychromatophilic cells than older children and adults.

Howell-Jolly body: the red blood cell in the center of the image contains a Howell-Jolly torso.  Howell-Jolly bodies are small (0.5-1 micron) purple inclusions that contain DNA.  They are thought to stand for chromosomes that have separated from the mitotic spindle that is left behind when the scarlet cell nucleus is extruded.  These inclusions are generally removed past the spleen.  Patients with asplenia or hyposplenism may have increased Howell-Jolly bodies on their peripheral blood smear.  A nucleated red blood jail cell is also present at the bottom left side of the image.

Blood Morphology – Erythroid Precursors

Proerythroblasts (too chosen pronormoblasts) are the earliest erythroid precursors.  These are big cells with basophilic, agranular cytoplasm, round nuclei, and high nuclear-cytoplasmic ratios.  The chromatin is evenly dispersed, simply is slightly more dense than myeloblast chromatin.  One or more nucleoli may exist visible.  A perinuclear articulate surface area (hof) may also be seen.  A single proerythroblast is seen in the center of this image.  Polychromatophilic and orthochromic normoblasts are nowadays on the right side of the field.

Proerythroblast

Basophilic normoblasts (also called basophilic erythroblasts or early erythroblasts) are smaller than proerythroblasts, with more than condensed chromatin and lower nuclear-cytoplasmic ratios.  The cytoplasm is deep bluish, and a pale perinuclear halo may present. The two cells in the heart of the field are basophilic normoblasts.

Early Erythroblasts

Orthochromic normoblasts (also called orthrochromatophilic normoblasts, orthrochromatophilic erythroblasts, or late erythroblasts) are slightly larger than mature scarlet blood cells.  They take minor, round nuclei and dense, pyknotic chromatin.  The cytoplasm is more often than not slightly more basophilic than the cytoplasm of a mature ruby-red claret cell.

Late Erythroblasts

Erythroid precursors at various stages of maturation.  Basophilic normoblasts are present at the center of the field.  Polychromatophilic normoblasts and orthochromic normoblasts are present nigh the bottom of the field.  As erythroid precursors mature, the jail cell size and nuclear-cytoplasmic ratio subtract, and the chromatin becomes progressively more than condensed.  The cytoplasm changes color from deep blue to grayness-blue to gray-pink as the hemoglobin content increases.

Erythroid Precursors

A deficiency of either vitamin B12 or folic acid results in megaloblastic erythroid cells-megaloblasts. These deficiencies upshot in a decrease in DNA synthesis which slows and inhibits DNA replication (nuclear partitioning). Nuclear maturation is slowed whereas cytoplasmic maturation (largely dependent on RNA role) is unaffected. The impaired nuclear maturation is seen as open, loose, immature chromatin (cut-salami pattern). In contrast to the nucleus, the cytoplasm of megaloblastic cells is abundant with normal hemoglobinization. This disparity between nucleus and cytoplasm is known as nuclear-cytoplasmic asynchrony. Although nigh noticeable in erythroid cells failure of DNA synthesis also affects myeloid and megakaryocytes. Giant bands and hypersegmented polymorphonuclear neutrophils are common.

Vacuolated erythroid precursors can be seen in copper deficiency, Pearson syndrome, and myelodysplastic syndromes.  In this image, a vacuolated erythroid precursor is adjacent to another dysplastic erythroid precursor with megaloblastic features (nuclear-cytoplasmic asynchrony) and nuclear irregularities.  The patient had acute myeloid leukemia with myelodysplasia-related changes.

White Blood Cell Morphology

Mature segmented neutrophils have condensed chromatin and 2 to 5 nuclear lobes separated by thin filaments.  The cytoplasm is pale pink and contains numerous specific granules.  In salubrious adults, approximately 40-80% of peripheral blood leukocytes are segmented neutrophils.

Band neutrophils are slightly less mature than segmented neutrophils and accept indented, unsegmented "C" or "S" shaped nuclei.  Band neutrophils normally business relationship for approximately v-10% of peripheral blood leukocytes.  An increased proportion of ring neutrophils tin exist seen in infectious and inflammatory conditions.

Toxic granulation in neutrophils is establish in inflammatory states. The toxic granules are azurophilic, and may be found in the promyelocyte, metamyelocyte, band (shown here), and mature stages.

Hypersegmented neutrophil in a patient with vitamin B12 deficiency.  Hypersegmented neutrophils accept half-dozen or more nuclear lobes. They are typically seen in megaloblastic anemia due to vitamin B12 or folic acid deficiency, but may also be present in myelodysplastic syndromes and rare congenital conditions.

Pelger-Huet anomaly is a congenital autosomal ascendant anomaly in which neutrophil nuclei fail to segment normally. In homozygotes, the nucleus is circular. In heterozygotes, well-nigh granulocytes have bilobed nuclei ("pince-nez" cells) resembling bands.

 Neutrophils with prominent hypolobation and Pseudo Pelger-Huet cytomorphology in a patient seen in the posttransplant setting. This patient was on mycophenolate which is sometimes known to induce such changes. One must be cautious non make a diagnosis of myelodysplastic syndrome in the setting.

Neutrophilic metamyelocytes have condensed chromatin and a slightly indented nucleus (the indentation is less than half the diameter of the nucleus). The cytoplasm contains arable specific granules and rare master (azurophilic) granules.  Metamyelocytes are not normally present in the peripheral blood, just can be seen in infectious or inflammatory states, and in other reactive and neoplastic conditions.

Myelocytes contain both primary (azurophilic) and secondary/specific (pinkish or lilac) cytoplasmic granules.  The proportion of secondary granules increases as the jail cell matures.  The nucleus is round and lacks a nucleolus.  The chromatin is more condensed than that of promyelocytes.  Myelocytes are not commonly nowadays in peripheral blood, but may be seen in infectious/inflammatory weather, growth factor consequence, marrow infiltration, and myeloid neoplasms.

Promyelocytes are larger than myeloblasts, and have basophilic cytoplasm containing master (azurophilic) granules.  A Golgi zone may exist visible as a paranuclear hof or clearing.  The nuclear chromatin is finely dispersed, and nucleoli may be visible.  Promyelocytes incorporate approximately ii% of nucleated cells in the os marrow and do non broadcast in peripheral claret under normal conditions.

Myeloblasts are approximately 15-twenty microns in size, and have high nuclear to cytoplasmic ratios.  The nucleus is usually round to oval, merely may be irregular.  The chromatin is smooth and open, and one or more than nucleoli may be nowadays.  The cytoplasm is pale bluish.  Cytoplasmic granules are not typically seen, though rare small granules may be present.  Leukemic myeloblasts may comprise few cytoplasmic granules or Auer rods, which are reddish, linear structures equanimous of fused chief granules.  The presence of Auer rods indicates myeloid malignancy.

Eosinophils measure 10-17 microns in diameter, and take abundant, slightly basophilic cytoplasm containing numerous coarse, reddish-orange cytoplasmic granules.   Most eosinophils have bilobed nuclei, just occasional forms with trilobed nuclei may be seen.  The chromatin is condensed.   Eosinophils usually account for a small-scale subset of peripheral blood leukocytes.  Increased numbers of eosinophils can be seen in parasitic infections, allergic weather, drug hypersensitivity, myeloid neoplasms, and lymphoproliferative disorders.

Basophils take segmented nuclei that are often at to the lowest degree partially obscured by abundant fibroid, dark blueish to royal cytoplasmic granules.  Basophil granules are water soluble, and may launder out during staining.  Basophils normally circulate in low numbers.  Basophilia may be seen in inflammatory and allergic conditions, hypothyroidism, and myeloproliferative neoplasms.

Normal resting lymphocytes are small cells with condensed chromatin and a small amount of pale basophilic cytoplasm.  The nucleus of a resting lymphocyte is but slightly larger than a red blood prison cell.

Reactive lymphocytes show a range of morphologic features.  Reactive lymphocytes with immunoblast-similar morphology are big cells with high nuclear-cytoplasmic ratios, condensed chromatin, and deeply basophilic cytoplasm.   Another type of reactive lymphocyte has less condensed chromatin and abundant, pale blueish cytoplasm that may announced to "hug" side by side red blood cells.  These cells are likewise called Downey type 2 cells.  They can be seen in a diversity of conditions, but are frequently increased in infectious mononucleosis due to EBV infection.

Lymphocytes with peripherally clumped chromatin and oft deep blueish cytoplasm similar to plasma cells are termed plasmacytoid lymphocytes. These transitional forms betwixt lymphocytes and plasma cells are seen in the blood of patients with viral infections. These cells are variously known as atypical lymphocytes, lymphocytoid plasma cells or plasmacytoid lymphocytes.

Monocytes measure 12-20 microns in diameter and take abundant grayish-bluish cytoplasm and fine, azurophilic cytoplasmic granules. Cytoplasmic vacuoles may exist present. The nucleus is irregular, indented, or kidney-shaped. Although the chromatin is condensed, it is somewhat finer than the chromatin of a mature neutrophil or resting lymphocyte.

Normal monocyte in circulation with folded nuclei and abundant vacuolated cytoplasm.

Acute monoblastic/monocytic leukemia: blasts may vary in appearance. The cytoplasm may contain fine granules or vacuoles.

Peripheral smear from a patient with monocytic leukemia. The monocytes are dysplastic with vacuolated and irregular cytoplasm.

References:

Teresa Scordino, MD. ASH Image Banking concern: https://imagebank.hematology.org/

Girish Venkataraman, MD. ASH Image Depository financial institution: https://imagebank.hematology.org/

Peter Maslak. ASH Image Depository financial institution: https://imagebank.hematology.org/

Paul C. Hattersley, Thou.D. and Judith 50. Engels, MT: The Reporting of Claret Morphology https://goo.gl/zr26TK

Hattersley, P.G., and Engels, J.L: Neutrophilic Hypersegmentation Without Macrocytic Anemia, West. J. Med. 121:179-184, 1974.

De Gruchy, G.C.: Clinical Hematology in Medical Practise, ed 2, Philadelphia: F.A. Davis Co., 1964, p. 63.

Hattersley, P.Grand., and Ragusa, D.: Don't Forget the Morphology: The Importance of Evaluation of Claret Smears, Calif. Med. 103:175-177, 1965.

Megaloblastic Anemia. Department of Pathology, Academy of Virginia, School of Medicine. https://www.med-ed.virginia.edu/courses/path/innes/rcd/mega.cfm

Summary

Article Proper name

Claret Morphology

Description

Blood morphology adds greatly to the value of a routine claret count. A skillful examination of a well-made claret smear constitutes the most valuable single procedure in the hematology laboratory.

Author

Dr. Moustafa Abdou

Publisher Proper noun

https://askhematologist.com/

Publisher Logo

Source: https://askhematologist.com/blood-morphology/

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