Blasts shouldn't be seen in peripheral blood.
Rule out leukemia, myelodysplastic syndrome, chronic myeloid leukemia.
Blasts may be other immature hematopoeitic cells. High monocyte count might actually be blasts, not monocytes.
If auto differential is abnormal, get a manual one.
Blasts newly elevated is more suggestive of acute leukemia. Pancytopenia suggests bone marrow failure. Febrile neutropenia is also concerning.
Make sure pt is stable with vitals, oxygen if needed, fluids.
Rule out emergencies and then contact heme/once.
APL is a subtype of AML. AML has 7 morphological categories using a system called fab. APL is the third subtype, M3. It has unique history and treatment. It presents with DIC and has early mortality. People hemorrhage and die. You can prevent it by giving all trans retinoic acid (ATRA). It helps APL cells differentiate into normal cells. APL is curable. Give all trans retinoic acid (ATRA). Diagnose by looking at source of the tumor cells. Look at peripheral blood smear. It separates ALL from AML. Auer rods are seen in AML. APL cells have multiple auer rods and folded nuclei that are very granulated.
CML has maturation of all the white cells, mature granulocytes, basophilia.
MDS (myelodysplastic syndrome) = elderly pts; hypogranular neutrophils, bilobed neutrophils, red cell shape/size changes (anisopoikilocytosis)*.
Do the peripheral blood smear first. Next do a peripheral blood flow cytometry or cell markers. It classifies cells based on the markers they express. Blasts express CD34. If CD34 is elevated, then the pt has increased blasts.
The definitive test to diagnose acute leukemia is a bone marrow biopsy. AML = more than 20% myeloblasts on bone marrow biopsy. ALL = more than 20% lymphoblasts on bone marrow biopsy.
APL has a characteristic genetic translocation--chromosome 15 and 17.
Before talking to heme/onc, also get bloodwork to rule out DIC (fibrinogen level, INR, PTT, d-dimer). If pt is febrile, work up includes blood culture, chest X-ray, urine culture for febrile neutropenia.
Also get CMP, phosphorus, magnesium, calcium, uric acid level to look for tumor lysis syndrome.
Transfuse platelets if platelets less than 10,000 and bleeding. If symptomatic anemia, transfuse RBCs.
Leukostasis = elevated WBCs such that blood flow to organs is impeded. Immature cells clog up the vasculature. Causes hypoxia, pulm infiltrates, SOB, AMS, HA, dizziness. WBC can be 50 to 100 or even less than that in leukostasis.
Other hematologic emergencies: cauda equina (spinal cord compression) is seen in lymphoproliferative disorders (lymphoma-> mass effect on spinal cord); myeloma (alters bone integrity-> compression fractures). Sometimes myeloma deposits can compress the spinal cord. So assess lower extremity reflexes, tone, Babinski sign, saddle anesthesia, rectal tone, bowel or bladder incontinence.
Top 5 clinical pearls
1) blasts are worrisome in peripheral blood, should not be in peripheral blood. Get heme/onc on board fast.
2) get a manual differential, review the film manually
3) acute leukemia can present with pancytopenia and no circulating blasts, OR with just circulating blasts. So either of those should be explored.
4) if you think the pt has acute leukemia, suspect APL, which is a medical emergency that can be treated with all trans retinoic acid immediately.
5) hematologic emergencies: severe cytopenia, febrile neutropenia, DIC, tumor lysis syndrome, leukostasis, cord compression. So screen for these.
*Anisopoikilocytosis is when you have red blood cells that are of different sizes and shapes.
The term anisopoikilocytosis is actually made up of two different terms: anisocytosis and poikilocytosis. Anisocytosis means that there are red blood cells of varying sizes on your blood smear. Poikilocytosis means that there are red blood cells of varying shapes on your blood smear.
So basically: get a peripheral blood smear, which let's you look at the cells. Flow cytometry can further differentiate the specific cell type that is elevated. Bone marrow biopsy is the definitive way to diagnose.
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