CAP Pro Course - Hematology - Erythrocyte Inclusions (2025 & 2026)

Author: Margaret A. Reinhart, MS, MT(ASCP)
Reviewers: Joshua J. Cannon, MS, MLS(ASCP)CMSHCM and Laurie Bjerklie, M.A., MLS(ASCP)CM

Continuing Education Credits

Objectives

  • Identify clinically relevant erythrocyte inclusions.
  • Choose the appropriate stain to aid in the identification of erythrocyte inclusions.
  • Differentiate erythrocyte inclusions from common peripheral blood smear observations.
  • Correlate clinical conditions with the presence of clinically relevant erythrocyte inclusions.

Course Outline

  • Identify clinically relevant erythrocyte inclusions.
      • Introduction to Erythrocyte Inclusions
      • Table 1. Erythrocyte Inclusions
      • What are the red blood cell inclusions in this Wright-stained peripheral blood smear?
      • The patient is a 21-year-old college student who returned two weeks prior from a trip to South America. What is the identity of the inclusions in the ...
      • What red cell inclusions are shown by the arrow in this Wright-stained peripheral blood film?
      • These images are from the blood of a 7-year-old boy with thalassemia who has had a splenectomy. The red cell inclusions illustrated in the upper image...
      • A 30-year-old woman experienced intermittent and persistent low-grade fever, fatigue, and muscle aches two weeks after participating in an outdoor cam...
      • This Wright-stained peripheral blood smear is from a 67-year-old woman with severe anemia of unknown cause. What erythrocyte inclusion is indicated by...
      • Identify the inclusion seen in this Wright-stained smear of peripheral blood from a 41-year-old patient.
  • Choose the appropriate stain to aid in the identification of erythrocyte inclusions.
      • Staining Methods to Detect Erythrocyte Inclusions
      • Table 2. Recommended Stains for Various Erythrocyte Inclusions
      • A slide is sent from automated hematology analysis for smear review. Multiple inclusions are seen on the Wright-stained slide. Which of the following ...
      • The automated hematology instrument is not functioning properly, and you cannot report reticulocyte counts from the instrument. How would you provide ...
      • Identify the stain that can be used for malarial detection other than a routine peripheral Wright-stained blood smear.
      • Which iron-containing inclusion is visible using Wright stain due to the presence of a protein matrix within the granules?
      • Your supervisor has asked that peripheral blood smear slides be prepared and stained manually for routine microscopic smear review while the automated...
      • A patient's automated CBC results show an increased population of large red blood cells. Upon microscopic review, you note an abnormal increase of lar...
      • The laboratory information system indicates that Heinz bodies were reported as present yesterday for this patient. You do not find them on today's rou...
  • Differentiate erythrocyte inclusions from common peripheral blood smear observations.
      • Extracellular Organisms, Cellular Blood Components, and Artifacts
      • Table 3. Conditions Impacting Erythrocyte Inclusion Identification
      • You observed this structure, indicated by the blue arrow, on a pediatric patient’s peripheral blood smear. What is the identity of this structur...
      • You are performing a manual review of a slide that shows evidence of moderate water contamination, although some areas appear unaffected. You note How...
      • A high number of erythrocytes (reported as 3+) resembling those in this image were observed on an adult patient’s Wright-stained peripheral bloo...
      • You identify potential extracellular yeast on a peripheral blood smear. The patient is being seen for a routine physical. What should your first step ...
      • An elevated result for which of these tests would help confirm the finding of polychromasia on a peripheral blood smear?
  • Correlate clinical conditions with the presence of clinically relevant erythrocyte inclusions.
      • Clinically Relevant Erythrocyte Inclusions
      • Table 4. Association of Erythrocyte Inclusions with Clinical Conditions
      • In which of the following conditions are the intraerythrocytic inclusions shown by the arrow in this Wright-stained peripheral blood film commonly see...
      • A 67-year-old man has been diagnosed with sideroblastic anemia. Which of the following inclusions consistent with this diagnosis would you expect to f...
      • This intracellular structure, along with numerous target cells, was observed on the Wright-stained peripheral blood smear of an 18-year-old college st...
      • Many factors influence the frequency of reported inclusion bodies seen during manual smear analysis. Of the choices below, which factor can influence ...
      • A 56-year-old woman has been diagnosed with myelodysplastic syndrome with a prominent anemia. There is a decrease in the red blood cell count and a di...
      • A 54-year-old patient with a recently documented bleeding event is seen in the emergency department (ED) for possible alcohol poisoning. On a Wright-s...
      • A 24-year-old patient with known sickle cell anemia is admitted to the hospital during an acute sickle cell crisis event. The patient's automated CBC ...
      • A 3-year-old is admitted to the hospital with severe lead poisoning. Which of the following inclusions, indicative of lead poisoning, is most likely t...
      • An emergency department (ED) patient has recently returned from a subtropical climate and is experiencing intermittent fevers, nausea, and severe leth...
  • References
      • References

Additional Information

Level of Instruction: Intermediate
Intended Audience: This program is designed as an educational and training tool for MLS, MT, and MLT personnel, medical laboratory science students and interns, pathology residents, and practicing pathologists. 
Author Information: Margaret Reinhart, MS, MT(ASCP) is the MLS Program Director and Senior lecturer in Biological Sciences at the University of the Sciences in Philadelphia, PA, where she teaches hematology, clinical immunology, parasitology, and other related courses. She is also an adjunct instructor in Hematology at Pennsylvania Hospital, Philadelphia PA. She holds a Masters Degree in Biology and Health Care Administration.
Reviewer Information:
Joshua J. Cannon, MS, MLS(ASCP)CMSHCM received his Bachelor of Science and Master of Science in Medical Laboratory Science from Thomas Jefferson University in Philadelphia, PA. He holds Medical Laboratory Scientist and Specialist in Hematology certifications through the ASCP Board of Certification. He was a professor at Thomas Jefferson University for seven years before transitioning into his current role as an Education Developer. His areas of expertise and professional passions include clinical hematology and interprofessional education.
Laurie Bjerklie, M.A., MLS(ASCP)CM, is currently an Education Developer. She earned a B.S. in Medical Laboratory Science from the University of North Dakota and an M.A. in Curriculum and Instruction from Saint Xavier University. She has over 14 years of experience in higher education and has held faculty positions in both MLT and MLS programs. She most recently served as the Program Manager of Medical Laboratory Science at Saint Louis University.
  
 

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