New Leukemia Diagnosis

AML, ALL, CML blast crisis, hyperleukocytosis — hematologic emergencies requiring urgent oncology evaluation and complication management

Symptoms / Associated Sx

  • Fatigue, pallor, exertional dyspnea (anemia)

  • Fever, infections (neutropenia)

  • Easy bruising, petechiae, spontaneous bleeding (thrombocytopenia)

  • Bone pain, arthralgias (marrow infiltration — ALL in children)

  • Lymphadenopathy, splenomegaly, hepatomegaly

  • CNS symptoms: headache, vision changes, cranial nerve palsies (leukemic meningitis — ALL)

  • Hyperleukocytosis (WBC >100k): Dyspnea, confusion, visual changes, priapism (leukostasis — medical emergency)

  • Gum hypertrophy, skin infiltration (AML M4/M5 monocytic subtypes)

Denies

  • Prior chemotherapy (rules out treatment-related AML if absent)

  • Prior myelodysplastic syndrome (MDS) or myeloproliferative neoplasm (reduces likelihood of de novo vs. secondary leukemia)

  • Sick contacts, travel (rules out infectious etiology of pancytopenia if absent)

Social History (SHx)

Prior malignancy (treatment-related AML after alkylating agents or topoisomerase inhibitors), radiation exposure, chemical exposure (benzene — AML), prior MDS, Down syndrome (AML/ALL), family history of hematologic malignancy.

Main Etiology

  • AML: Clonal expansion of myeloid blasts (>20% blasts in marrow); de novo or secondary (MDS, prior chemo); median age ~68; mutations: FLT3, NPM1, CEBPA guide prognosis and targeted therapy

  • ALL: Clonal B- or T-cell lymphoblasts; bimodal (children peak 2–5 years, adults >50); Philadelphia chromosome (BCR-ABL) in 25% of adult ALL — worst prognosis without targeted therapy

  • CML blast crisis: Accelerated CML evolving to blast phase (>20% blasts); BCR-ABL mutation; TKI failure or resistance

  • Hyperleukocytosis: WBC >100k → leukostasis (sludging in microvasculature) → organ ischemia; most common in AML (monocytic subtypes) and CML

Most Common DDx

  • Leukemoid reaction (WBC elevated but <100k; reactive; infection, severe inflammation, marrow stress; no blasts on smear; left shift; resolves with treatment of underlying cause)

  • Aplastic anemia (pancytopenia without circulating blasts; hypocellular marrow on biopsy; no organomegaly; younger patients; treated differently — immunosuppression or transplant)

  • Lymphoma with marrow involvement (lymphadenopathy + splenomegaly + cytopenias; biopsy shows lymphoma cells not blasts; CT staging; lymph node biopsy)

  • Myelodysplastic syndrome (MDS) (pancytopenia + dysplastic cells on smear; <20% blasts; marrow biopsy distinguishes from AML; higher-risk MDS → AML-like treatment)

  • Infectious mononucleosis / EBV (atypical lymphocytes on smear; fever + lymphadenopathy + pharyngitis; monospot or EBV serology positive; self-limited)

  • Reactive thrombocytosis / leukocytosis (infection, inflammation, post-splenectomy; normal differential without blasts; smear normal morphology)

DATA

  • CBC with differential (blast %; ANC; Hgb; platelets — full cytopenias common)

  • Peripheral blood smear (blast morphology — Auer rods in AML; lymphoblasts in ALL)

  • Comprehensive metabolic panel (tumor lysis labs: uric acid, LDH, potassium, phosphorus, calcium, creatinine)

  • Coagulation panel (DIC screen — PT, PTT, fibrinogen, D-dimer — especially AML M3/APL)

  • LDH (elevated — tumor burden marker)

  • Uric acid (hyperuricemia — TLS risk)

  • Bone marrow biopsy + aspirate (gold standard — morphology, flow cytometry, cytogenetics, FISH, molecular panel)

  • Flow cytometry (immunophenotyping — myeloid vs. lymphoid; CD markers)

  • Cytogenetics (karyotype) + molecular panel (FLT3, NPM1, IDH1/2 for AML; BCR-ABL for ALL/CML)

  • LP (lumbar puncture) with cytology (ALL — CNS involvement; symptoms or standard protocol)

  • CT chest/abdomen/pelvis (lymphoma differentiation; organomegaly; mediastinal mass in T-ALL)

  • Echo (cardiac function — pre-anthracycline baseline)

  • HLA typing early (allogeneic transplant planning)

Home Meds

  • Prior TKI therapy (CML — imatinib, dasatinib, nilotinib; check compliance and resistance mutations)

  • All prior chemotherapy agents (treatment-related AML risk)

  • Allopurinol or rasburicase (if previously prescribed for uric acid management)

Plan

  • Oncology/hematology consult immediately — all new leukemia requires specialist management

  • Immediate stabilization:

    • Transfuse pRBCs if Hgb <8 (phenotypically matched; irradiated and CMV-negative for transplant candidates)

    • Transfuse platelets if <10k or active bleeding (irradiated; target >20k if febrile; >50k for procedures)

    • Correct coagulopathy (DIC — see DIC section; especially critical in APL/AML-M3)

  • Tumor lysis syndrome (TLS) prophylaxis (start immediately):

    • IV hydration: 3 L/m² IV daily (high flow to promote uric acid excretion)

    • Allopurinol 300 mg PO/IV daily (prevents new uric acid formation; does not reduce existing uric acid)

    • Rasburicase (Elitek) 0.2 mg/kg IV × 1 dose (converts uric acid to allantoin — rapidly lowers uric acid; use if uric acid >8 or high TLS risk; contraindicated in G6PD deficiency — causes hemolysis)

    • Monitor electrolytes q6–8h: uric acid, K+, phosphorus, calcium, creatinine

  • Hyperleukocytosis (WBC >100k) — leukostasis emergency:

    • Leukapheresis (cytoreduction) — indications: symptomatic (CNS or pulmonary leukostasis); WBC >100k in AML or >300–400k in CML; rapidly rising WBC

    • DO NOT transfuse pRBCs until WBC reduced — increases blood viscosity and worsens leukostasis

    • Hydroxyurea 1–3 g PO TID as bridge to leukapheresis or definitive therapy

    • Aggressive hydration

  • APL (AML-M3) — specific emergency:

    • ATRA (all-trans retinoic acid) 45 mg/m² PO divided BID START IMMEDIATELY if APL suspected (do not wait for confirmation — fatal coagulopathy)

    • Arsenic trioxide added once diagnosis confirmed

    • Aggressive DIC management (see DIC section)

  • AML (non-APL) induction chemotherapy (oncology-directed):

    • Standard: "7+3" — cytarabine 100–200 mg/m² continuous infusion × 7 days + daunorubicin/idarubicin × 3 days

    • Targeted: add midostaurin (FLT3+) or venetoclax + azacitidine (older/unfit patients)

  • ALL induction: Hyper-CVAD or pediatric-inspired protocol; add dasatinib/ponatinib if Ph+ ALL (BCR-ABL positive) — oncology directed

  • Neutropenic fever protocol if febrile during admission (see neutropenic fever section)

  • Allopurinol or rasburicase throughout induction; IV hydration throughout

  • Strict neutropenic precautions; irradiated/CMV-neg blood products

  • Echo before anthracycline chemotherapy; HLA typing for transplant planning

  • Daily CBC, CMP, TLS labs; trend coagulation panel (APL)

  • PT/OT; nutritional support; psychology/social work (new diagnosis)

  • Discharge: Oncology follow-up within days for consolidation planning; CBC monitoring schedule; fever precautions; TLS monitoring; hydroxyurea or TKI (CML); clinic schedule for bone marrow re-staging

Red Flags

  • APL (AML-M3) + DIC + bleeding → START ATRA immediately without waiting for confirmation; fatal coagulopathy can kill within hours

  • Hyperleukocytosis WBC >100k + CNS/respiratory symptoms → leukostasis emergency → leukapheresis urgently; do NOT transfuse pRBCs

  • CNS symptoms (headache, cranial nerve palsies) in ALL → LP + intrathecal chemotherapy; CNS prophylaxis essential

  • Acute TLS (hyperkalemia + hyperphosphatemia + hypocalcemia + AKI) → ICU; nephrology; rasburicase; dialysis if refractory

  • Mediastinal mass in T-ALL → airway compression → anesthesia emergency if sedation required; treat without delay

Senior IM Resident Pearls

  • Auer rods on peripheral smear = AML until proven otherwise (pathognomonic — myeloperoxidase-positive azurophilic rods in blast cytoplasm)

  • APL recognition is life-saving: DIC + WBC often LOW (not elevated) + promyelocytes on smear → START ATRA empirically; do not wait for flow cytometry confirmation

  • Rasburicase contraindicated in G6PD deficiency — causes severe hemolysis; check G6PD or use allopurinol instead in high-risk populations (African, Mediterranean, Southeast Asian)

  • Philadelphia chromosome (BCR-ABL) in adult ALL is present in ~25–30% and historically indicates worst prognosis; however, ponatinib + steroids ± chemo achieves excellent remission rates without transplant in some patients

  • Common mistake: Transfusing pRBCs in hyperleukocytosis — increases viscosity, worsens leukostasis, and can precipitate respiratory or neurologic failure; reduce WBC first with leukapheresis or hydroxyurea

  • Common mistake: Waiting for bone marrow results before starting ATRA in suspected APL — the diagnostic window is too dangerous; start empirically and stop if APL is ruled out

Labs

  • CBC with differential

  • Peripheral smear

  • CMP

  • Magnesium

  • Phosphorus

  • LDH

  • Uric acid

  • PT/INR

  • PTT

  • Fibrinogen

  • D-dimer

  • Type & Screen

  • Type & Cross

Leukemia Workup

  • Flow cytometry

  • Bone marrow biopsy/aspirate

  • Cytogenetics (karyotype)

  • FISH

  • Molecular panel

    • FLT3

    • NPM1

    • IDH1/2

    • BCR-ABL

TLS Monitoring

  • BMP q6–8h

  • Phosphorus q6–8h

  • Uric acid q6–8h

  • Calcium q6–8h

  • Creatinine q6–8h

  • LDH daily

If Febrile

  • Blood cultures ×2

  • UA

  • Urine culture

  • CXR

Pre-Chemo

  • Hepatitis B panel

  • Hepatitis C Ab

  • HIV

  • G6PD level (before rasburicase if possible)

  • HLA typing

Trending

  • CBC daily (often BID initially)

  • CMP daily

  • Coags daily

  • TLS labs q6–8h

Imaging

  • CXR

  • CT Chest/Abdomen/Pelvis

  • Echocardiogram (before anthracycline)

If CNS Symptoms

  • CT Head

  • MRI Brain

If T-ALL Suspected

  • CT Chest (mediastinal mass)

Meds – TLS Prophylaxis

IV Fluids

  • NS 100–200 mL/hr
    OR

  • 3 L/m²/day

Goal:

  • Urine output >100 mL/hr

Allopurinol

  • 300 mg PO daily

High TLS Risk

  • Rasburicase 0.2 mg/kg IV ×1

Avoid if G6PD deficiency.

Hyperleukocytosis (WBC >100k)

Hydroxyurea

  • 1–3 g PO TID

Aggressive IV Hydration

  • NS 100–200 mL/hr

Leukapheresis

  • Consult hematology/apheresis urgently

Important

  • Avoid pRBC transfusion until leukostasis improves if possible

APL (AML-M3) Suspected

ATRA

  • 45 mg/m²/day PO divided BID

START IMMEDIATELY.

Do NOT wait for bone marrow confirmation.

Transfusions

pRBC

  • Hgb <7 generally

  • Hgb <8 if symptomatic, ACS, CAD, active bleeding

Use:

  • Irradiated blood products

  • CMV-negative if transplant candidate

Platelets

  • <10k → transfuse

  • <20k if febrile

  • <50k if procedure or bleeding

If DIC / APL

  • Cryoprecipitate to keep fibrinogen >150

  • FFP PRN

  • Platelets to goal >30–50k

Neutropenic Fever (if develops)

Cefepime

  • 2 g IV q8h

OR

Piperacillin-Tazobactam

  • 4.5 g IV q6h

Add Vancomycin if indicated.

Consults

  • Hematology/Oncology STAT

  • Apheresis Team (hyperleukocytosis)

  • Transfusion Medicine

  • Nephrology (TLS/AKI)

  • ICU (leukostasis, TLS, DIC, shock)

  • Radiation Oncology (rare emergencies)

  • Social Work

  • Nutrition

  • Psychology

Monitoring

  • Telemetry

  • Strict I&O

  • Daily weights

  • Monitor for bleeding

  • Monitor for TLS

  • Neutropenic precautions

VTE Prophylaxis

  • Enoxaparin 40 mg SQ daily

Hold if:

  • Severe thrombocytopenia

  • Active bleeding

Use SCDs if pharmacologic prophylaxis contraindicated.

Therapy

  • PT/OT evaluate and treat

  • Nutrition consult

Procedures

  • Bone marrow biopsy

  • PICC placement if chemotherapy planned

  • LP if ALL/CNS symptoms

Discharge Criteria

  • Hemodynamically stable

  • TLS controlled

  • No active bleeding

  • Definitive leukemia plan established

  • Oncology follow-up arranged