1. Normal peripheral blood: Smear contains granulocytes, a relatively uniform red cell population, and platelets.
2. Normal bone marrow aspirate: Heterogenous population with maturing elements in multiple lineages.
3. Myeloid blast with Auer rods: Immature cell with high nuclear cytoplasmic ratio and distinctive cytoplasmic inclusions.
4. Chronic myelogenous leukemia—bone marrow aspirate: Hypercellular aspirate with increased M:E ratio and eosinophilia.
5. Mast cell leukemia—bone marrow aspirate: Irregular, immature cells with metachromatic staining granules.
6. Essential thrombocythemia—bone marrow biopsy: Megakaryocytes are increased and appear in clusters.
7. Myelodysplastic syndrome—bone marrow aspirate: Dysplastic erythroid elements are increased and display nuclear cytoplasmic asynchrony.
8. Ring sideroblasts (MDS)—bone marrow aspirate with iron stain: Iron stain demonstrates abnormal localization in the perinuclear mitochondria.
9. Acute monocytic leukemia—bone marrow aspirate: Blasts appear regular with ample cytoplasm.
10. Acute promyelocytic leukemia—bone marrow aspirate: Heavy granulation obscures the nuclear cytoplasmic border.
11. Acute myeloid leukemia with myelodysplasia-related changes—bone marrow aspirate: Blasts are increased with dysplastic changes in other lineages.
12. Acute myelomonocytic leukemia—bone marrow aspirate: Marrow contains both immature monocytic and myeloid elements with characteristic baso-eosinophils.
13. Acute megakaryocytic leukemia—bone marrow aspirate: Blasts are undifferentiated with cytoplasmic blebs.
14. Pure erythroid leukemia—bone marrow aspirate: Proerythroblasts predominate the marrow.
15. Blastic plasmacytoid dendritic cell neoplasm—bone marrow aspirate: Rare disorder is classified with the myeloid leukemias.
16. Acute lymphoblastic leukemia—bone marrow aspirate: Blasts with scant cytoplasm and smooth nuclear chromatin.
17. Adult T-cell leukemia/lymphoma—peripheral blood: Characteristic “flower cells” circulate in the blood.
18. T-cell prolymphocytic leukemia—peripheral blood: Malignant cells often have indistinct nucleoli and irregular nuclear contours.
19. Sézary syndrome—peripheral blood: Cells have folded, irregular nuclei.
20. Plasma cell leukemia—peripheral blood; circulating plasma cells are often accompanied by rouleaux formation in the red blood cells.
21. Chronic lymphocytic leukemia—bone marrow aspirate: Marrow replaced by well-differentiated lymphocytes.
22. Hairy cell leukemia—bone marrow aspirate: Cells have characteristic cytoplasmic projections.
23. Multiple myeloma with Dutcher bodies—bone marrow aspirate: Sheets of plasma cells with distinctive nuclear inclusions.
24. Metastatic breast cancer—bone marrow biopsy: Tumor cells disrupt the normal marrow architecture.