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PA15.1-3 | Welcome to Peripheral Smear of Macrocytic Anaemia — Practical

Learning Objectives

  • Apply a systematic approach to reading a peripheral blood smear for macrocytic anaemia.
  • Identify and name the key morphological features: macro-ovalocytes, hypersegmented neutrophils, anisopoikilocytosis, Howell-Jolly bodies, and Cabot rings.
  • Distinguish megaloblastic from non-megaloblastic macrocytosis on the smear.
  • Correlate peripheral smear findings with MCV, leucopenia, and thrombocytopenia in severe megaloblastic disease.
  • Describe where and how to read a smear for optimal cellular morphology.

INSTRUCTIONS

This practical module walks you through reading a macrocytic anaemia smear step by step — from selecting the right zone on the slide to recognising each diagnostic feature. Work through each section, engage with the self-check questions, and then attempt the four-panel smear challenge at the end. This is the skill that lets you confirm a suspected B12/folate deficiency at the bench, before the MCV result arrives.

References

  • Robbins & Kumar: Basic Pathology, 11th ed., Ch 14 (Red Cell Disorders) (textbook)
  • Dacie & Lewis: Practical Haematology, 12th ed., Ch 3 (Blood Film Examination) (textbook)
  • Harsh Mohan: Textbook of Pathology, 8th ed., Ch 12 (Disorders of Red Blood Cells) (textbook)

Version 2.0 | NMC CBUC 2024