Differential Information and Courses from MediaLab, Inc.

This cytospin is from a patient diagnosed with Acute Myeloid Leukemia (AML) who had central nervous system involvement at the time of diagnosis.Notice the large size of these blasts. They have very fine, soft chromatin with very prominent multiple nucleoli. The cytoplasm has a hint of the background granularity that myeloid blasts have on a peripheral smear. These characteristics help to identify immature myeloid blast cells in fluid differential analysis.

The white cell clump in this image contains budding yeast and matted branching hyphae contained within it.If you look away from the clump, the yeast and hyphae are not obvious. This is why it is important to always take a close look at any white cell clumps that are present on a cytospin. It is good practice to check fluid differential cell clumps for the presence of infectious organisms.

For the clinical laboratory professionals who are only familiar with peripheral blood morphology, the first few observations of bone marrow aspirate smears can be overwhelming. The difference in cellularity between the two sample types, not to mention the wider variety of cell types, can lead to mental and visual overload. It is important to step back and break it down into more manageable pieces, starting on low power. Use low power (10x) to look at the distribution on the slide and the quality of the stain. Find areas where the spread/distribution of cells are thin enough (monolayer) to read easily and where you like the color balance and intensity of the stain. Next, add oil and move up to 50x and/or 100x power on the microscope.* Remember that there are several different cell types that are normally present and develop in the bone marrow before heading out into the peripheral blood. Most hematology technologists are familiar with the myeloid maturation sequence from peripheral differentials, even if immature cells are less commonly seen. However, there are additional cell types that are not seen on the peripheral blood differential, since they reside only in the bone marrow. Becoming more familiar with these cell types and the maturation sequences of the myeloid, erythroid, and megakaryocytic cells found in normal bone marrows will make performing these differentials less intimidating.One important concept to grasp is the continuum of cellular maturation sequences. There is no such thing as a magical switch that flips causing cells to jump to the next "textbook photo stage" as cell lines mature. Rather, each cell matures at its own pace. The maturation and morphology will vary from cell to cell and bone marrow to bone marrow. Understanding both nuclear and cytoplasmic normal morphology can aid in the identification of cells. *As counter-intuitive as it sounds for most applications, higher magnification does not always help with morphology. Reserve 100x for ultra fine detail.

Depending on the institution and laboratory protocol, comments on the degree of cellularity, presence of megakaryocytes, and presence of tumor cells may be added to the report by the technologist who performs the differential count. The terms used to describe these features will be determined by the hematopathologist.Cellularity is usually rated as normal, increased, or decreased. However, other terms may be used as well, such as "slightly decreased," "markedly decreased," or "markedly increased," etc. When spicules/fragments are not present, terms like "hemodilute" can be used to note very dilute bone marrows or, it may simple be marked as "not evaluable". For megakaryocytes the common terms of quantitation may be: None Seen Rare Decreased Present Normal Increased The presence of tumor cells should be noted as well as the slide or site in which they were observed. The top image on the right demonstrates a bone marrow that is markedly hypocellular. Only fragments of the bone marrow structure are present, with very few bone marrow precursor cells observed. Compare this to the bottom image that depicts a bone marrow that is normocellular.

It is important to note that not all smears will have good areas to perform a differential in the vicinity of the bone marrow fragment. When this occurs, you must keep looking on additional smears. This is one of the reasons that several smears are stained and prepared for possible review. It can take time to recognize from 10x magnification what will be countable on 50x magnification. The best tip is to be patient and do not fail to keep on looking! In fact, sometimes it may be necessary to stain additional smears/slides, if available, to obtain enough readable material. While you are checking the smears on 10x magnification for readable areas, you should take the time to evaluate and record the following: The cellularity of the bone marrow sample Presence and number of megakaryocytes Presence of tumor cells Anything else out of the ordinary, which should be noted on the report (such as evidence of hemophagocytosis, storage disease etc.).Once you have decided where to count the marrow, you will perform the differential count. Usually a 200-cell bone marrow differential is the minimum acceptable count. However, more cells may be required depending on your laboratory/pathology protocol. Remember, unlike peripheral differentials, all nucleated cells are included in the total count, including all maturation stages of the erythroid cell series.Cell counts are performed on 40 - 50x magnification with oil depending on the optics of your scope, moving up to 100x magnification with oil as needed for fine detail. Once oil is added to the smear, move systematically through your chosen area until the morphology/cellularity/stain quality is no longer acceptable, then move back to 10x power to find another good area in the vicinity of the fragment to continue your count. You may need to progress from one slide to the next to accumulate enough cells for your differential. In fact, if there is variability in cell distribution from one smear or fragment/spicule to the next, then the count should be split between more than one smear/fragment to avoid a biased final count.If there are no spicules, then the differential should be performed in any portion of the slide that demonstrates readable morphology. In pull preps and coverslip preps, this will usually be in the thin area near the edge of the smear. If differential-type (wedge) smears are available, then the usual feathered-edge area should be used. On any of these smears, be sure that you are in deep enough from the thin edge so that the numbers of stripped cells are kept at a minimum to avoid skewing the count, as some cell types are more fragile than others.The pathologist is ultimately responsible for the final sign-out and will change/adjust/return smears for recount if there is any disagreement over numbers and cell types.

Plasma cells are terminally differentiated B-lymphocytes that have developed a characteristic morphology while actively producing and releasing immunoglobulins. While plasma cells have their origins in the bone marrow as B-cells, they usually leave the bone marrow to develop and mature in the lymph nodes or spleen. Plasma cells begin to produce immunoglobulins after being stimulated by T-cells and exposed to processed antigens.Under normal circumstances, plasma cells are not a large percentage of the lymphoid cells found in a marrow. They are usually placed in a separate category in the differential, unlike viral/atypical lymphs. There can be a relative increase in plasma cells in reactive marrows, and both plasma cells and their early precursors will be markedly increased in plasma cell disorders.While mature plasma cells somewhat resemble lymphocytes, there are a few important differences. The size of the cell is usually larger with more abundant cytoplasm. The nucleus is eccentrically placed and the overall shape of the cell generally resembles a wedge or comet with the nucleus leading the cytoplasm. The chromatin is just as thick and clumpy as a lymphocyte's but is aligned in a more "spokey" or "clockwork" pattern. The cytoplasm is usually more basophilic than the cytoplasm of a normal lymphocyte and will have a well-defined perinuclear halo or noticeable clearing in the golgi area. Vacuoles may or may not be present.Notice the size of the single plasma cell in the top image (see red arrow). It is larger than the neutrophil precursors surrounding it and is almost rectangular in shape. Observe that the nucleus leads the cytoplasm, causing the wedge or comet shape. Notice the prominent perinuclear halo. Find the two plasma cells in the upper left corner of the second image. There is much more cytoplasm in these plasma cells compared to the occasional lymphocyte present in the field. Notice the eccentric nuclear placement as well as the characteristic clearing in the golgi area.

Stromal cells are the cells that comprise the backbone of a bone marrow fragment. They provide the support matrix as well as some of the nutrients necessary for the growth of all cellular precursors found in the bone marrow.Stromal cells appear similar to macrophages and tend to be found in sheets. Usually, they are deep in the heart of a fragment. When the differential is counted in the areas adjacent to the fragments, they may not be noticed and should not be counted. While stromal cells may be present in clusters, it is important to recognize that these cells are normal bone marrow elements and are not tumor cells.In aplastic bone marrows, or bone marrows with decreased cellularity, they may be more apparent. However, since they are considered tissue cells, they are not included in the differential. The top image to the right demonstrates a typical stromal clump. The bottom image shows stromal cells mixed with phagocytic macrophages.

Citron DM. Appelbaum PC.: How far should a clinical laboratory go in identifying anaerobic isolates, and who should pay? Clinical Infectious Diseases. 16 Suppl 4:S435-8, 1993 Identification of anaerobic bacteria in specimens from sites of infection due to mixed organisms can be time-consuming and expensive. Laboratories should limit anaerobic workups by testing only those specimens that have been properly collected and transported to the laboratory. Use of selective and differential media for initial processing can provide rapid and relevant information to the clinician. Anaerobes isolated from normally sterile sites and sites of serious infection should always be completely identified. Group-or genus-level identifications may suffice in other instances. The Bacteroides fragilis group of organisms should always be identified because of their virulence and resistance to many antimicrobial agents. Some of the other organisms that warrant identification include Clostridium septicum (associated with gastrointestinal malignancy); Clostridium ramosum, Clostridium innocuum, and Clostridium clostridioforme (which are resistant to antibiotics); Clostridium perfringens (a cause of myonecrosis and gas gangrene,potentially serious infection); anaerobic cocci (which may be resistant to metronidazole and clindamycin); and fusobacteria (which may be virulent and resistant to clindamycin and penicillin).

The tubes used for CSF aspiration are generally pre-numbered 1 through 3 or 4, with tube 1 being the first tube filled. If possible, tube 1 should be reserved for non-routine studies. Tube 2 can be used for immunology and chemistry testing. Tube 3 can be used for microbiology testing. Hematology analysis is typically performed on the last tube collected (3 or 4) to assure that any peripheral blood that may have contaminated the sample during the lumbar puncture has cleared. When only three tubes are obtained:Tube 2 is often reserved for microbiology Tube 3 is shared, with the hematology testing performed first, followed by any chemistry or immunology testing. The first tube obtained should not be used for microbiology or hematology testing because of possible contamination from the lumbar puncture. However, in some health care facilities, a red blood cell (RBC) count may be requested on the first tube of CSF collected and the last tube collected as a means of differentiating a subarachnoid hemorrhage (SAH) from a traumatic tap. If the RBC counts in the first and last tubes are similar, an SAH is suspected. If the RBC count in the last tube is significantly less than the count in the first tube, a traumatic tap is suspected.One problem that could occur with this method is if a traumatic tap is overlying a subarachnoid hemorrhage and the presence of blood in the last tube is due to an SAH. The two-tube count can raise the suspicion of an SAH, but a question still remains whether this is the cause or is the residual blood due only to the traumatic tap, but the volume of CSF collected is insufficient to allow the CSF to clear. When a large number of RBCs are present in the last tube, but less than the number in the first tube, the physician must use additional clinical information to determine if an SAH is present.

In an undiluted specimen, count and differentiate red cells and white cells at the same time. You can count red cells on a hand counter and use the differential counter for white cells. If you cannot differentiate white cells from red cells in the undiluted specimen, a plain capillary tube may be filled with crystal violet acetic acid diluent which is subsequently expelled from the tube. A very thin coating of the diluent will remain on the inside of the tube. CSF is drawn halfway up into the tube, which is then rocked back and forth to mix. The hemacytometer is then filled with the fluid containing stained white blood cells and lysed red cells. If cells are numerous and overlapping and it is necessary to focus through several planes in order to see all of the cells, a dilution must be made. When macroscopic appearance is turbid, milky or bloody, a significant dilution is usually necessary.

The cytospin technique uses a high speed centrifuge to concentrate the cells on a slide in a uniform monolayer 6 mm in diameter. The monolayer distribution enhances the morphological appearance of the cells present.Allow the slides to dry in air for several minutes and then stain them with Wright-Giemsa stain. Cytospin slides may be placed in an automatic stainer or stained manually.Perform a 100 or 200 cell differential and record the number of neutrophils, eosinophils, basophils, lymphocytes, monocytes, macrophages, and blasts cells.Pathologists must review any slide which has tumor cells, unidentified cells, or immature stages of cells, such as blasts.Since criteria for review may vary from one laboratory to another, be sure to check the requirements in your laboratory before reporting the differential.

Bilirubin may be present in the urine when bile duct obstruction, liver disease, or liver damage is present. Bilirubinuria can be detected before other clinical symptoms, such as jaundice, are present or recognizable. The detection of small quantities of bilirubin is very important in early diagnosis of obstructive and hepatic jaundice. The urine bilirubin test is also useful in the differential diagnosis of obstructive jaundice (positive for bilirubinuria) vs. hemolytic jaundice (negative for bilirubinuria).

Atherosclerosis. U.S. Department of Health & Human Services National Institutes of Health. Available at http://www.nhlbi.nih.gov/health/dci/Diseases/Atherosclerosis/Atherosclerosis_WhatIs.html Accessed March 25, 2013.Daniels LB, Barrett-Connor E, Sarno M, Laughlin GA,Bettencourt R, Wolfert RL. Lipoprotein-associated phospholipase A2 (Lp-PLA2) independently predicts incident coronary heart disease (CHD) in an apparently healthy older population: The Rancho Bernardo study. J Am Coll Cardiol. 2008;51:913-919.Executive Summary of the third report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III). JAMA. 2001; 285:2486-2497. Frostegard, J, Wu R, Lemne C, Thulin T, Witztum JL and de Faire U. Circulating oxidized low-density lipoprotein is increased in hypertension, Clin Sci 2003; 105, 615.Garza CA, Montoir VM, McConnell JP, et al. Association between lipoprotein-associated phospholipase A2 and cardiovascular disease: a systematic review. Mayo Clin Proc. 2007;82(2):159-165.Interpretive Handbook, (MC0440rev0407) Mayo Clinic, RochesterMN;2007. Maksimowicz-McKinnon K, Bhatt DL, Calabrese LH: Recent advances in vascular inflammation: C-reactive protein and other inflammatory biomarkers. Curr Opin Rheumatol. 2004;16:18-24.Mora S, Szklo M, Otvos JD, et al. LDL particle subclasses, LDL particle size, and carotid atherosclerosis in the multi-ethnic study of atherosclerosis. Atherosclerosis. 2007;192:211-217.NACB Laboratory Medicine Practice Guidelines. Emerging biomarkers of cardiovascular disease and stroke. NationalAcademy of Clinical Biochemistry Laboratory Medicine Practice Guidelines. 2006.PLACtest animation, diaDexus. http://www.plactest.com/laboratorians/action.php Accessed March 25, 2013.Rifai N, Warnick GR. Lipids, lipoproteins, apolipoproteins, and other cardiovascular risk factors. In: BurtisCA, Ashwood ER. BrunsDE. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 4th ed. St. Louis, MO: Elsevier Saunders: 2006; chap. 26.Ridker PM, Rifai N, Rose L, et al. Comparison of C-reactive protein and low-density lipoprotein cholesterol levels in the prediction of first cardiovascular events. N Engl J Med. 2002;347:1557-1565.Sniderman AD. Differential response of cholesterol and particle measures of atherogenic lipoproteins to LDL-lowering therapy: Implications for clinical practice. J Clin Lipidol 2008;2:36-42.Tsimikas, S, Brilakis ES, Miller ER, et al. Oxidized phospholipids, Lp(a) lipoprotein, and coronary artery disease, N Engl J Med: 2005;353:46.Tsimikas S, Bergmark C, Beyer RW, et al. Temporal increases in plasma markers of oxidized low-density lipoprotein strongly reflect the presence of acute coronary syndromes. J Am Coll Cardiol. 2003; 41: 360.Tsimikas, S, Lau HK, Han KR, et al. Percutaneous coronary intervention results in acute increases in oxidized phospholipids and lipoprotein(a): Short-term and long-term immunologic responses to oxidized low-density lipoprotein. Circulation. 2004;109, 3164.Tsimikas S, Witztum JL, Miller ER, Sasiela WJ, et al. High-dose atorvastatin reduces total plasma levels of oxidized phospholipids and immune complexes present on apolipoprotein B-100 in patients with acute coronary syndromes in the MIRACL trial, Circulation: 2004;110, 1406. Walldius G, Jungner I, Holme I, et al. High apolipoprotein B, low apolipoprotein A-I, and improvement in the prediction of fatal myocardial infarction (AMORIS study): a prospective study. Lancet. 2001;358:2026-2033.Yusuf S, Hawken S, Ounpuu S, et al. Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study): case-control study. Lancet. 2004;364:937-952.

In addition to hereditary hemochromatosis (HH), there are other conditions of iron overload that must be considered in a differential diagnosis. Disorders such as sickle cell disease, thalassemia, sideroblastic anemia, congenital dyserythropoietic anemia, and liver disease may also cause iron overload. Transfusion-dependant patients and persons who abuse iron-containing vitamin supplements are also at risk. These conditions are usually described as secondary iron overload, in contrast to the primary iron overload of HH.Patient history, clinical signs and symptoms, biochemical and hematologic laboratory analyses, and possibly results of a liver biopsy may be needed to establish a diagnosis of a condition causing secondary iron overload. DNA tests for common HFE mutations are very likely the most important diagnostic tool for identifying HH as the cause of iron overload. In some patients, both secondary causes and HH may be contributing to iron overload. Differentiating the secondary causes of iron overload from HH is heavily dependent on the results of laboratory assays, but a complete discussion is beyond the scope of this course.

Examination of Wright-Giemsa stained bone marrow preparation involves examination under low power (10X objective) high power (40-50X objective )and oil immersion (100X objective). Low power examination: Assess quality of smear, assess number of megakaryocytes.Assess myeloid to erythroid ratio.Evaluate morphology and do differential count.

A 60-year-old man presented to the emergency department with complaints of fatigue and weakness which began during the previous week. He also stated that he had been experiencing shortness of breath without chest pain, cough, or dizziness. Upon physical examination, he had normal vital signs. However, his spleen was mildly enlarged. Laboratory tests were ordered. The white blood count (WBC) and absolute lymphocyte counts were both elevated:WBC= 28.5 x 109/L (normal 4 - 10) Lymphocyte count= 20.0 x 109/L (normal 1.2 - 4.0)A manual differential confirmed the elevated lymphocyte count. Smudge cells were also noted, as shown in the image.To evaluate the patient's lymphocytosis, a blood sample was submitted for flow cytometry analysis.

Traditional culture methods for the detection and identification of methicillin-resistant Staphylococcus aureus (MRSA) employing mannitol salt and/or blood agar for cultivation, can take up to 72 hours for isolation and identification, depending on the identification procedures utilized. Concurrent with the development of molecular assays, improvements in culture methods have also been achieved. CHROmagar™ media, specific for MRSA, are employed by many laboratories. These media are both selective and differential, containing chromogenic substrates. MRSA strains utilize the substrates to produce colonies of a specific and characteristic color, minimizing the need for additional identification procedures.Initially these agars required 48 hours of incubation; newer formulations require only 24 hours incubation.Given the reduced incubation and identification requirements, what are the pros and cons of the molecular assays? Cost per test will be greater with the molecular assays as compared to culture methods. Will molecular methods provide for a more efficient workflow and significant improvement in availability of results? To some extent, this will depend on how they can be implemented within each different laboratory setting. Both of the previously described molecular assays require manual specimen preparation and extraction before the sample is placed into the instrument. This hands-on work may actually be greater than the effort expended in swabbing and streaking a culture plate. How much an obstacle this is for implementation will depend on both the volume of testing and the staff available. In a high volume setting, this will be a greater factor.Will tests be performed as specimens come in, or will specimens be accumulated and batched? If controls are required with each run, batching is desirable to reduce this cost. If testing will occur in batches, how many batches can be performed in one day? This will be heavily influenced by the capacity of the instrument. (For example, a single Smart Cycler unit can run up to 16 samples; multiple units would be needed in a high volume lab.) Can they be set up on more than one shift? The greater the number and frequency of batches that can be run, the greater improvement in turnaround time can be realized. Given these variables, implementation of a molecular assay for MRSA is not a given in each laboratory.

Surveillance is a critical component of any program for controlling multi-drug resistant organisms (MDROs). Many institutions are using active surveillance cultures to identify patients who are colonized with a targeted MDRO. With respect to MRSA, an increasing number of hospitals are screening patients upon admission and on a periodic basis (usually weekly). The anterior nares is the primary site that is swabbed for screening.There are several selective and/or differential media that can be used for this purpose.Baird Parker Agar is a selective medium for the isolation of S. aureus; on this medium S. aureus produces black colonies with a clear halo.Mannitol Salt Agar is also a selective medium; S. aureus produces yellow colonies which contrast with the red color of the medium.Chromogenic agars have been developed for the isolation and presumptive identification of different species of bacteria and yeast. The media are formulated so that as different organisms utilize various substrates in the media, the organism of interest produce colonies with a unique color. Chromogenic agars specifically designed for the detection of MRSA are commercially available.In addition to culture methods, there are now commercially available, FDA approved methodologies for screening for MRSA by PCR. Although equipment and cost factors may not make these a viable option for every laboratory, they may offer greater sensitivity and improved turnaround times.

If multiple primary receptacles are placed in a single secondary packaging, they must be either individually wrapped or separated so as to prevent contact between them.The primary receptacle or the secondary packaging must be capable of withstanding, without leakage, an internal pressure producing a pressure differential of not less than 95 kPa (13.8 lbs/in2) because the package may be placed into an unpressurized storage compartment in a cargo aircraft. This must be verified when choosing packaging for shipping either category A or category B substances by aircraft. It is also recommended if shipping by ground. An evacuated blood collection tube that has remained unopened qualifies as a 95 kPa container. The smallest surface of the outer packaging must be at least 100 mm X 100mm (4 inches x 4 inches).Other dangerous goods must not be packed in the same packaging as Division 6.2 infectious substances unless they are necessary for preservation of the specimen (e.g., formalin). A quantity of 30 mL or less of formalin or other dangerous goods included in hazard Classes 3, 8, or 9 (flammable liquids such as alcohol; corrosives such as acids or bases; or miscellaneous hazardous materials) may be packed in each primary receptacle containing infectious substances. A quantity greater than 30 mL will require appropriate hazard labels on the package.OverpackWhen packages are placed in an overpack, the overpack must be marked with the word "Overpack" and the package markings must be reproduced on the outside of the overpack.

Gram stain is used primarily as a differential stain for bacteria, although it will also stain most fungi (especially yeasts) and some parasites, including Strongyloides and Trichomonas. The Gram stain procedure is commonly performed on direct smears of clinical specimens and on smears from cultures. This course will focus on Gram-stained direct smears. A direct smear from a clinical specimen can be used to: Judge the quality of the specimen. Provide the clinician with same-day information regarding possible pathogenic organisms, pending results of culture and sensitivity. Contribute to selection of culture media, especially with mixed flora. Provide internal quality control when direct smear results are compared to culture results.

Recognition and identification of RBC morphologic abnormalites can be an invaluable aid in the diagnosis of a variety of disorders. Observation of RBC morphology from a properly prepared smear will also confirm the red cell indices reported by the hematology analyzer.RBC morphology can be visualized by examining erythrocytes on a Wright, or Wright-Giemsa stained peripheral blood smear. Evaluation of red cell morphology involves differentiating normal morphology from abnormal and artifactual morphology.

Red blood cells can vary in size (diameter/volume) from smaller than normal, microcytes, to larger than normal, macrocytes. When red cells of normal size, microcytes and macrocytes are present in the same field, the term anisocytosis is used. Since the purpose of this unit is to acquaint you with the appearance (identification) of abnormal red cell morphology, percentages of abnormalities present will not be considered. It is important to be aware that rating red cell morphology for the purpose of reporting it is a skill which must be learned before you are able to complete this aspect of a differential count.

Diagnosis of allergic reactions is based on the recognition of a skin rash associated with itching. Treatment involves temporarily discontinuing the transfusion and administering an antihistamine. The rash will usually heal when the transfusion is stopped or when an antihistamine is given. Once symptoms have been alleviated, the transfusion may be resumed. If symptoms continue or progress, the transfusion must be stopped and a new donor unit obtained. Premedication will usually prevent urticarial reactions in patients with a history of allergic reactions. If premedication is unsuccessful, washed cellular products may prevent a reaction. Leukoreduction has no role in preventing an allergic reaction. Anaphylatic and anaphylactiod reactions should be recognized when patients develop symptoms described on the previous page. The transfusion must be stopped immediately. Differential diagnosis includes hypotensive reactions, transfusion-related acute lung injury (TRALI), myocaridal infarction, and pulmonary embolus. An IgA deficiency should be investigated and is confirmed by the presence of anti-IgA. Treatment includes timely administration of epinephrine in addition to other supportive care such as vasopressors and airway support. Prevention involves avoiding transfusion of IgA. Cellular products should be washed to remove residual plasma. Products may also be collected from donors who are known to be IgA deficient. Autologous donations are an alternative.

Automated cell counters will flag abnormal findings. The following guidelines represent typical review criteria, although specific requirements vary between laboratories. Follow the criteria established by your laboratory's procedure:Total white blood cell count <3.0 X 109/L or >12.0 X 109/LNeutrophils >80% Lymphocytes >45% or <10% Monocytes >15% Eosinophils >10% Basophils >5%A morphology review may also be indicated if the platelet count is <100 X 109/L or >650 X 109/L.

May-Hegglin anomaly is an inherited dominant condition in which large (2 - 5 um) basophilic inclusions, resembling Döhle bodies, are present in granulocytes, including neutrophils, eosinophils, basophils, and monocytes. The inclusions are caused by accumulation of free ribosomes. A May-Hegglin body is indicated by the black arrow in the image on the right. Note that this inclusion is well-defined and there is no evidence of toxic granulation in the cytoplasm. When Döhle-like bodies are identified, May-Hegglin anomaly should be considered in the differential diagnosis, even though this entity is rare. Giant platelets containing few fine granules are also characteristic of May-Hegglin anomaly. The red arrow in the image on the right points to a giant platelet, observed in the same field as a neutrophil containing a May-Hegglin body. Sometimes the platelets have bizarre shapes and variable sizes. Variable degrees of thrombocytopenia complicated by mild bleeding problems and purpura may accompany the aberrant platelets.