Which cytoplasmic inclusion is classically seen in acute promyelocytic leukemia?

Which cytoplasmic inclusion is classically seen in acute promyelocytic leukemia?

• A. Dohle bodies
• B. Smudge cells
• C. Auer rods
• D. Heinz bodies

Answer: (C)

Auer rods are needle-like azurophilic inclusions inside myeloid blasts and are classic for acute myeloid leukemia, especially the promyelocytic (acute promyelocytic leukemia) subtype. They form from clumps of fused primary (azurophilic) granules, so their presence within blasts is a strong indication of myeloid lineage and supports an AML diagnosis. In the context of acute promyelocytic leukemia, you’ll often see many promyelocytes packed with these rods, which helps clinch the diagnosis. This subtype is also notable for a risk of disseminated intravascular coagulation and its sensitivity to all-trans retinoic acid therapy. Dohle bodies are seen as small ribosomal inclusions in neutrophils during toxic changes from infections or burns. Smudge cells are fragile lymphocytes often described in chronic lymphocytic leukemia. Heinz bodies are denatured hemoglobin inclusions seen in G6PD deficiency or unstable hemoglobins.

Auer rods are needle-like azurophilic inclusions inside myeloid blasts and are classic for acute myeloid leukemia, especially the promyelocytic (acute promyelocytic leukemia) subtype. They form from clumps of fused primary (azurophilic) granules, so their presence within blasts is a strong indication of myeloid lineage and supports an AML diagnosis. In the context of acute promyelocytic leukemia, you’ll often see many promyelocytes packed with these rods, which helps clinch the diagnosis. This subtype is also notable for a risk of disseminated intravascular coagulation and its sensitivity to all-trans retinoic acid therapy.

Dohle bodies are seen as small ribosomal inclusions in neutrophils during toxic changes from infections or burns. Smudge cells are fragile lymphocytes often described in chronic lymphocytic leukemia. Heinz bodies are denatured hemoglobin inclusions seen in G6PD deficiency or unstable hemoglobins.