At the Bedside
- Think of it in a patient with known CML or prior myeloproliferative disease who now has worsening fatigue, fevers, bruising/bleeding, dyspnea, confusion, bone pain, or abdominal fullness.
- Exam clues: pallor, petechiae, ecchymoses, fever, sternal tenderness, hepatosplenomegaly, neuro changes from leukostasis, or respiratory distress.
- Initial workup: CBC with differential, peripheral smear, CMP, uric acid, LDH, phosphorus, potassium, calcium, creatinine, coagulation studies, fibrinogen, type/screen, blood cultures if febrile, ECG if electrolyte concern.
- Look for emergencies:
- Leukostasis: headache, vision changes, dyspnea, confusion, hypoxemia; more common with very high WBC and blasts.
- Tumor lysis syndrome: hyperK, hyperphos, hyperuricemia, hypocalcemia, AKI.
- DIC/bleeding: especially if acute promyelocytic leukemia is in the differential.
- Resuscitation: IV access, fluids if tolerated, treat fever as sepsis until proven otherwise, transfuse as needed. Avoid unnecessary RBC transfusion if hyperviscosity/leukostasis is a concern unless profound symptomatic anemia.
- Definitive ED actions: urgent hematology/oncology consultation, admission—usually ICU if leukostasis, TLS, DIC, or organ dysfunction. Cytoreduction may be started by hematology (e.g., hydroxyurea; leukapheresis is considered in selected leukostasis cases).
- Disposition: never discharge; this is a same-day admit with specialist involvement.
A Classic Presentation
A 48-year-old man with known CML arrives with worsening shortness of breath, headache, and gum bleeding. He is tachycardic, mildly hypoxemic, and has petechiae and splenomegaly. CBC shows WBC 180,000 with circulating blasts, hemoglobin 7.1, platelets 14,000, uric acid elevated, and creatinine rising. He is treated as blast crisis with urgent heme/onc consultation, IV fluids, TLS labs, blood product support, and admission to the ICU for cytoreduction and close monitoring.
Patient Presentation to Attending
How you’d present this patient on the floor
This is a 48-year-old man with known CML presenting with progressive dyspnea, headache, and mucosal bleeding over the last day. My main concern is blast crisis with possible leukostasis and tumor lysis, because he has a very high WBC with circulating blasts plus neurologic and respiratory symptoms. He’s also thrombocytopenic with bleeding, which raises concern for marrow failure and consumptive complications. On exam he’s tachycardic, mildly hypoxic, and has petechiae with splenomegaly; he’s not showing focal neurologic deficits or frank hemodynamic collapse right now. His labs show marked leukocytosis, anemia, thrombocytopenia, and rising uric acid/creatinine, which fits high-risk malignant transformation. I’ve started IV fluids, sent TLS/DIC labs, and I’ve contacted heme/onc for urgent cytoreduction planning and ICU admission.
Study Directive
- Draw the pathway from chronic phase CML → accelerated phase → blast crisis from memory.
- Make a one-page “malignant hyperleukocytosis” algorithm: leukostasis, TLS, DIC, infection, transfusion caveats.
- Practice ordering the first 8 labs you want and explain why each matters.
- Review when hydroxyurea is used in the ED and what is specialist-driven.
- Do 5 board questions on leukemia complications and say aloud why leukostasis is a clinical diagnosis.