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Section 2 of 6 · Open sections

Required section · Section 2 of 6

Build a reusable model of reactive change

Toxic granulation is increased prominence of primary, azurophilic granules in neutrophils. Its conspicuity varies with stain intensity and film quality, so compare cells across the film and with a validated local atlas. Döhle bodies are pale blue cytoplasmic inclusions that correspond ultrastructurally to rough endoplasmic reticulum aggregates.

Cytoplasmic vacuoles may accompany activation or phagocytosis, but they are not specific for infection or sepsis. Delayed preparation of a film from EDTA-anticoagulated blood can cause vacuolation, degranulation, and degenerative nuclear change. Collection-to-smear time and storage conditions are therefore part of the morphology observation.

A reactive left shift means increased circulating granulocytic precursors, commonly bands with possible metamyelocytes and myelocytes. Blasts, abnormal promyelocytes, or an otherwise unexplained immature population require a different pathway rather than routine reactive labeling. Name each visible feature, then state what specimen and maturation context makes that feature interpretable.

Illustrative drawing — this picture was drawn rather than captured.

Table of written morphology criteria, not a diagnostic photomicrograph. Lists toxic granulation, Döhle body, vacuolation, and specimen timing with the criteria to document for each, and states that diagnosis cannot be inferred from morphology alone.
Figure 1Written criteria table, not a diagnostic photomicrograph. Features to document in a reactive-appearing neutrophil.

Illustrative drawing — this picture was drawn rather than captured.

Labeled text boxes, not a diagnostic photomicrograph. Promyelocyte, myelocyte, metamyelocyte, band, and segmented neutrophil are arranged in maturation order with written nuclear-shape criteria for each stage, and bands with earlier precursors are marked as reactive left shift.
Figure 2Labeled maturation sequence, not a diagnostic photomicrograph. Written nuclear-shape criteria for recognizing a reactive left shift.

Use this sequence before assigning a reactive morphology interpretation.

  1. Observe and describe

    Record granules, inclusions, vacuoles, nuclear detail, distribution, and focus behavior.

  2. Add specimen and CBC context

    Check collection-to-smear interval, storage, film quality, differential, and analyzer flags.

  3. Classify the look-alike

    Separate reactive features from stain artifact, storage degeneration, inherited morphology, and concerning immature cells.

  4. Apply local policy

    Release the approved comment, request a fresh smear when indicated, or escalate the review.

Knowledge checks

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Knowledge check 1

Which findings require specimen age or storage context before interpretation? Select all that apply.

Choose at least 2 options.

Knowledge check 2

Which finding should not be explained away as a routine reactive left shift?

Choose one option.

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