Blood & Lymphoreticular

Acute lymphoblastic leukemia in adults: management

Clinical Overview and When to Suspect Adult ALL

— Pancytopenia or unexplained cytopenias with circulating blasts

— Rapidly evolving fatigue, bruising, bleeding, recurrent infections over days–weeks

— Bone pain, lymphadenopathy, hepatosplenomegaly, mediastinal mass (especially T-ALL in young males)

— Unexplained CNS symptoms (headache, cranial neuropathy) with cytopenias — ALL has high CNS tropism

— Testicular mass in a male with cytopenias

— Prior chemo/radiation (therapy-related)

— Down syndrome (lifelong risk)

— Ionizing radiation exposure

— No strong infectious or familial trigger in most adult cases

Adult acute lymphoblastic leukemia (ALL) is an aggressive clonal proliferation of lymphoid precursors (B-cell ~75%, T-cell ~25%) presenting with marrow failure and frequent extramedullary involvement

Bimodal epidemiology — peak in childhood, second peak after age 50; adult outcomes substantially worse than pediatric (5-yr OS ~40% vs >85%)

Suspect ALL in any adult with:

Distinguish from AML clinically only with marrow flow cytometry — never on smear alone

Key distinction: Adult ALL ≠ pediatric ALL in management. Adults have higher rates of Ph+ disease (BCR::ABL1 in ~25–30% of B-ALL vs <5% in children), older biology, and require pediatric-inspired regimens when fit, plus TKI integration when Ph+

Risk factors are mostly idiopathic but include:

Board pearl: A previously healthy adult presenting with fever + petechiae + lymphadenopathy + circulating blasts mandates urgent hematology consultation and admission, not outpatient workup. Do not delay for outpatient bone marrow — the patient needs tumor lysis prophylaxis, blood product support, and definitive flow cytometry within 24 hours

Step 3 framing tends to test (1) recognizing the syndrome, (2) initiating supportive care correctly, (3) knowing Ph+ ALL adds a TKI, and (4) CNS prophylaxis is mandatory in all subtypes

Presentation Patterns and Key History

— Anemia → fatigue, dyspnea on exertion, pallor, exertional angina in older adults

— Thrombocytopenia → epistaxis, gum bleeding, menorrhagia, petechiae, easy bruising

— Neutropenia → fever, recurrent sinopulmonary or perianal infections, oral ulcers

— Bone or joint pain (marrow expansion) — prominent in young adults, may mimic rheumatologic disease

— Painless lymphadenopathy, often cervical or generalized

— Early satiety, LUQ fullness from splenomegaly

— Mediastinal mass (T-ALL) → cough, dyspnea, SVC syndrome, stridor

— CNS involvement (~5–10% at diagnosis) → headache, vomiting, cranial nerve palsies (especially CN VI, VII), meningismus

— Testicular enlargement (males) — sanctuary site

— Prior chemotherapy/radiation (therapy-related ALL alters prognosis and regimen choice)

— Down syndrome

— Performance status (drives intensive vs attenuated therapy decision)

— Comorbidities: cardiac (anthracyclines), hepatic (asparaginase), prior thromboembolism (asparaginase risk), diabetes (steroid effect)

— Reproductive plans — fertility preservation referral before chemo initiation

— Vaccination history, HBV/HCV/HIV status, TB exposure (before immunosuppression)

Classic syndrome evolves over 2–6 weeks, faster than CLL or myelodysplasia

Marrow failure symptoms (from blast crowding):

Proliferative/infiltrative symptoms:

Constitutional: low-grade fever, night sweats, weight loss — overlaps with lymphoma

Critical history elements to capture on Step 3:

Board pearl: A young man with a mediastinal mass, lymphocytosis, and SVC syndrome is T-ALL until proven otherwise — secure airway plans, avoid sedation that drops preload, and obtain tissue urgently

Step 3 management: Document baseline performance status (ECOG) and frailty in older adults — this single data point dictates whether you offer pediatric-inspired intensive therapy vs lower-intensity regimens (e.g., blinatumomab-based, mini-hyperCVD)

Physical Exam Findings and Hemodynamic Assessment

— Fever (infection vs leukemia itself), tachycardia from anemia, hypotension if septic or in tumor lysis with cardiac dysrhythmia

— Tachypnea — consider pneumonia, leukostasis (uncommon in ALL vs AML), or mediastinal compression

— Pallor of conjunctivae and palmar creases

— Petechiae (lower extremities, palate), ecchymoses, oozing gums

— Leukemia cutis is rare in ALL (more typical of monocytic AML)

— Cervical, axillary, inguinal lymphadenopathy — usually painless, mobile, rubbery

— Splenomegaly in ~50%, hepatomegaly in ~30%

— Tonsillar enlargement, especially in T-ALL

— Dullness to percussion or decreased breath sounds → mediastinal mass or pleural effusion

— Pemberton sign (facial plethora on arm elevation) in mediastinal mass with SVC compression

— Cranial nerve palsies (VI, VII most common) — exam every admission

— Papilledema, nuchal rigidity → CNS leukemia or hemorrhage

— Identify neutropenic fever — single oral temp ≥38.3°C or ≥38.0°C sustained 1 hr with ANC <500 → empiric cefepime or piperacillin-tazobactam within 1 hour after blood cultures

— Identify tumor lysis–related arrhythmia — hyperkalemia ECG changes (peaked T, widened QRS)

— Identify SVC syndrome — facial edema, distended neck veins, upper extremity swelling

— Identify DIC — diffuse oozing from line sites, hypotension; check fibrinogen, D-dimer, PT/PTT

General/vitals:

Skin/mucosa:

Lymphoid system:

Chest:

Neuro:

GU: testicular asymmetry, painless enlargement in males

MSK: sternal or long-bone tenderness on palpation

Hemodynamic priorities on Step 3:

CCS pearl: On the CCS case, your first orders for a suspected ALL admission should include: CBC w/ diff, peripheral smear, CMP, LDH, uric acid, phosphate, calcium, coags + fibrinogen, DIC panel, type & screen, blood cultures ×2, CXR, ECG, IV access, IVF, allopurinol or rasburicase

Diagnostic Workup — Initial Labs, Imaging, Biomarkers

— WBC variable — leukocytosis with blasts, normal count, or leukopenia

— Anemia (normocytic), thrombocytopenia common

— Blasts on smear with high N:C ratio, scant agranular cytoplasm, fine chromatin, indistinct nucleoli; no Auer rods (those imply AML)

— Uric acid, K+, phosphate, calcium, creatinine, LDH

— Elevated LDH and uric acid even before treatment suggest spontaneous TLS

— PT, aPTT, fibrinogen, D-dimer — DIC less common than in APL but possible, especially with infection or asparaginase therapy

— HIV, HBsAg/anti-HBc/anti-HBs, HCV Ab, HSV/VZV serology, CMV, strongyloides if from endemic area, QuantiFERON or PPD

— HBV core antibody positive → antiviral prophylaxis (entecavir or tenofovir) during therapy

— CXR — mediastinal mass, infection

— CT chest/abdomen/pelvis if lymphadenopathy or organomegaly

— Echocardiogram before anthracycline (baseline LVEF)

— Testicular ultrasound if exam abnormal

CBC with differential and peripheral smear:

Tumor lysis labs at baseline and q6–8h after therapy initiation:

Coagulation panel:

Comprehensive metabolic panel: baseline LFTs, renal function (dosing), glucose (steroid management)

Infectious workup before immunosuppression:

Imaging:

ECG: baseline QTc (TKIs and antifungals prolong QT)

Pregnancy test in all reproductive-age females

Board pearl: Spontaneous tumor lysis syndrome (high LDH, high uric acid, AKI before any chemotherapy) flags very high tumor burden — start rasburicase, not allopurinol, plus aggressive IV hydration. Avoid alkalinization (worsens calcium phosphate precipitation)

Key distinction: ALL blasts are PAS-positive, myeloperoxidase (MPO) negative; AML blasts are MPO positive. But flow cytometry — not cytochemistry — is the modern diagnostic standard

Diagnostic Workup — Advanced/Confirmatory Studies

— ≥20% lymphoblasts establishes acute leukemia

— Send aspirate for morphology, flow cytometry, cytogenetics (karyotype + FISH), and molecular studies

— B-ALL: CD19+, CD22+, CD79a+, TdT+, often CD10+ (common B-ALL); surface Ig negative (mature B = Burkitt, treated differently)

— T-ALL: cytoplasmic CD3+, CD7+, TdT+, variable CD4/CD8

— Mixed-phenotype acute leukemia if both myeloid and lymphoid markers — rare, complex

— t(9;22) BCR::ABL1 (Philadelphia chromosome) — present in ~25% of adult B-ALL; mandates TKI addition (imatinib, dasatinib, ponatinib)

— KMT2A (MLL) rearrangements — high risk, poor prognosis

— Hypodiploidy (<44 chromosomes) — high risk

— Ph-like ALL — gene expression profile resembling Ph+ without BCR::ABL1; targetable kinase fusions (CRLF2, JAK2, ABL-class)

— t(12;21) ETV6-RUNX1 — favorable (mostly pediatric)

— iAMP21, complex karyotype — adverse

— CSF cell count, cytology, flow cytometry

— First IT dose (methotrexate ± cytarabine + steroid) given at same procedure — combines diagnosis and prophylaxis

Bone marrow aspirate + biopsy is the diagnostic gold standard:

Flow cytometry immunophenotyping distinguishes lineage and subtype:

Cytogenetics and molecular — critical for risk and therapy:

Lumbar puncture with intrathecal chemotherapy is performed at diagnosis once platelets ≥50K and stable:

HLA typing at diagnosis in all candidates for allogeneic transplant — don't wait until consolidation

Fertility preservation referral before cytotoxic therapy — sperm banking, oocyte/embryo cryopreservation

Board pearl: Always test for BCR::ABL1 in adult B-ALL — missing Ph+ status means missing TKI therapy, which is the single largest survival modifier in this subgroup

Step 3 management: Defer LP until coagulopathy corrected and platelets ≥50K to prevent traumatic tap and iatrogenic CNS seeding

Risk Stratification and First-Line Management Logic

— Age (≥35 worse; ≥60 substantially worse)

— WBC at diagnosis (B-ALL >30K, T-ALL >100K = high risk)

— Cytogenetics/molecular (Ph+, KMT2A, hypodiploidy, complex = high risk)

— Immunophenotype (early T-precursor ALL high risk)

— Measurable residual disease (MRD) after induction — the strongest dynamic prognostic factor

— CNS involvement at diagnosis

— By multiparameter flow cytometry or PCR/NGS at end of induction (~day 28) and again after consolidation

— MRD-positive (≥0.01%) → switch to blinatumomab (CD19/CD3 BiTE) to clear MRD, then proceed to allogeneic HSCT

— Induction (4–6 weeks): vincristine, anthracycline, corticosteroid (prednisone/dexamethasone), asparaginase, ± cyclophosphamide

— CNS prophylaxis — intrathecal chemo throughout, sometimes cranial RT

— Consolidation/intensification — high-dose methotrexate, cytarabine, rotating agents

— Maintenance — 6-mercaptopurine + weekly methotrexate + monthly vincristine/prednisone pulses, 2–3 years total

— Adults <40 fit: pediatric-inspired regimens (CALGB 10403, BFM-based) — better OS than traditional adult protocols

— Adults 40–60 fit: hyperCVAD or pediatric-inspired with dose modifications

— Adults >60 or unfit: mini-hyperCVD + inotuzumab ± blinatumomab, lower-intensity backbones

— Ph+ ALL any age: TKI + chemo backbone (or TKI + blinatumomab in older/unfit)

Risk stratification drivers in adult ALL:

MRD assessment:

Treatment phases (universal framework):

Regimen choice by age/fitness:

Allogeneic HSCT in CR1 for high-risk features (Ph-like, KMT2A, persistent MRD, hypodiploidy) — Ph+ patients on modern TKI + blinatumomab regimens may avoid transplant if MRD-negative

Board pearl: MRD positivity after induction is the single most actionable prognostic marker — it overrides classical cytogenetic risk and prompts immunotherapy escalation and transplant evaluation

Pharmacotherapy — First-Line Regimens

— Cycle A: hyperfractionated Cyclophosphamide, Vincristine, Adriamycin (doxorubicin), Dexamethasone

— Cycle B: high-dose Methotrexate + high-dose Cytarabine

— Intrathecal methotrexate + cytarabine for CNS prophylaxis each cycle

— Maintenance: POMP (6-MP, methotrexate, vincristine, prednisone) ×2–3 years

— Vincristine, pegaspargase, daunorubicin, prednisone, cyclophosphamide, cytarabine, 6-MP, methotrexate

— Greater asparaginase exposure than adult regimens — drives improved outcomes but increases toxicity (thrombosis, pancreatitis, hepatotoxicity, hyperglycemia)

— Dasatinib or ponatinib preferred over imatinib; ponatinib + blinatumomab + steroids (chemo-free) shows excellent CR/MRD outcomes

— TKI continued through maintenance and often indefinitely

— Blinatumomab (CD19×CD3 BiTE) — for MRD+ disease or relapsed/refractory; consolidation in newly diagnosed CD19+ B-ALL (now standard add-on in many protocols)

— Inotuzumab ozogamicin (anti-CD22 ADC) — relapsed/refractory; risk of sinusoidal obstruction syndrome (VOD), especially pre-transplant

— Tisagenlecleucel/brexucabtagene (CAR-T) — relapsed/refractory; CRS and ICANS toxicity

— Tumor lysis prophylaxis: allopurinol (low/intermediate risk) or rasburicase (high risk, high WBC, high LDH, renal dysfunction); aggressive IV hydration

— PJP prophylaxis: TMP-SMX (or atovaquone if cytopenic)

— Antifungal prophylaxis: posaconazole or voriconazole during neutropenia (avoid azoles with vincristine — neurotoxicity)

— Antiviral prophylaxis: acyclovir

— G-CSF after induction to shorten neutropenia

HyperCVAD (alternating cycles A and B, 8 cycles total):

Pediatric-inspired (CALGB 10403): preferred for AYA (adolescent/young adult) ≤40

Ph+ ALL: add TKI to backbone

Immunotherapy integration (B-ALL):

Supportive pharmacology — must order routinely:

Step 3 management: Don't co-administer azole antifungals with vincristine simultaneously — severe neurotoxicity (ileus, neuropathy). Hold azole around vincristine days or use micafungin

Expanded Pharmacology — Toxicity Management & Novel Agents

— Thrombosis (CNS sinus thrombosis especially) — anticoagulate with LMWH; antithrombin repletion if low

— Pancreatitis — discontinue permanently if severe

— Hepatotoxicity — transaminitis, hyperbilirubinemia; usually reversible

— Hyperglycemia — insulin, not oral agents

— Hypersensitivity — switch to Erwinia asparaginase

— Hypofibrinogenemia and hypoalbuminemia — monitor; replace fibrinogen if bleeding

— Cytokine release syndrome (CRS) — fever, hypotension; pretreat with dexamethasone

— Neurotoxicity (ICANS-like) — encephalopathy, seizures, aphasia; hold drug

— Continuous IV infusion via ambulatory pump — patient education on pump failure

Asparaginase (pegaspargase) toxicity — high-yield:

Vincristine: peripheral neuropathy (cumulative), constipation/ileus, SIADH; cap dose at 2 mg (controversial in modern regimens)

Anthracyclines (daunorubicin, doxorubicin): cardiomyopathy — track cumulative dose; baseline and surveillance echo; dexrazoxane in selected cases

Methotrexate (high-dose): mucositis, nephrotoxicity, hepatotoxicity — leucovorin rescue, urinary alkalinization (pH >7.0), aggressive hydration; glucarpidase if MTX levels remain dangerously elevated

Cytarabine (high-dose): cerebellar toxicity (assess gait/dysmetria before each dose, hold if abnormal); conjunctivitis (prophylactic steroid eye drops); palmar-plantar erythema

Cyclophosphamide: hemorrhagic cystitis — mesna and hydration; SIADH

Glucocorticoids: hyperglycemia, infection, psychiatric effects, avascular necrosis (especially femoral head in AYAs)

Blinatumomab toxicities:

Inotuzumab ozogamicin: sinusoidal obstruction syndrome (VOD) — RUQ pain, weight gain, hyperbilirubinemia, ascites; risk worsened by subsequent HSCT — minimize cycles and time to transplant

CAR-T (tisa-cel, brexu-cel): CRS (tocilizumab), ICANS (steroids, supportive), prolonged B-cell aplasia → IVIG replacement

Board pearl: VOD/SOS after inotuzumab classically presents within weeks of transplant with painful hepatomegaly, jaundice, fluid retention — early defibrotide improves survival

Special Populations — Elderly and Renal/Hepatic Impairment

— Avoid hyperCVAD intensity; use mini-hyperCVD (reduced cyclophosphamide and methotrexate, no anthracycline) + inotuzumab ± blinatumomab

— Ph+ older adults: TKI (dasatinib or ponatinib) + blinatumomab + steroids — chemo-free induction with excellent CR rates and tolerable toxicity

— Geriatric assessment before therapy: functional status, comorbidities, cognition, social support

— Lower threshold for transplant deferral; consider reduced-intensity conditioning allogeneic HSCT in fit older patients with high-risk disease

— Dose-adjust methotrexate (avoid high-dose MTX if CrCl <60 unless aggressive support), cytarabine, cyclophosphamide

— Rasburicase contraindicated in G6PD deficiency (hemolysis, methemoglobinemia) — screen before use in at-risk populations

— Aggressive hydration, but balance against cardiac/renal capacity

— Maintain urine output >100 mL/hr during high-tumor-burden induction

— Vincristine, anthracyclines hepatically cleared — dose-reduce per bilirubin

— Asparaginase already hepatotoxic — caution with baseline LFT elevation

— 6-mercaptopurine in maintenance — check TPMT and NUDT15 genotypes; deficient patients need dose reduction or alternative to prevent fatal myelosuppression

— Baseline echo before anthracyclines; cumulative doxorubicin <450 mg/m²

— Consider liposomal anthracyclines or dexrazoxane in borderline LVEF

Older adults (≥60): historically dismal outcomes (5-yr OS ~10–20%) due to adverse biology (more Ph+, more complex karyotype) and intolerance of intensive chemo

Modern approach in older/unfit:

Renal impairment:

Hepatic impairment:

Cardiac comorbidity:

Diabetes: steroids and asparaginase worsen glycemia — basal-bolus insulin during induction

Board pearl: TPMT and NUDT15 testing before 6-MP is a Step 3 pharmacogenomics favorite — homozygous deficiency causes life-threatening myelosuppression with standard dosing

Step 3 management: Elderly Ph+ ALL no longer means hospice — TKI + blinatumomab delivers durable remissions even in patients in their 70s with comorbidities

Special Populations — Pregnancy, AYAs, Down Syndrome

— ALL during pregnancy is rare but urgent — maternal survival depends on prompt therapy

— First trimester: chemotherapy is teratogenic (methotrexate, cyclophosphamide especially) → discuss therapeutic termination vs delayed therapy; if continuing pregnancy, avoid antimetabolites

— Second/third trimester: modified regimens (vincristine, anthracyclines, steroids) generally safe; avoid methotrexate throughout pregnancy

— Deliver around week 34–37 when feasible to allow postpartum intensification

— Avoid chemotherapy within 3 weeks of expected delivery (neonatal myelosuppression)

— Breastfeeding contraindicated during chemo

— Multidisciplinary: heme-onc, MFM, neonatology, ethics

— Outcomes substantially better with pediatric-inspired regimens delivered at AYA-experienced centers

— Address adherence, fertility preservation, psychosocial issues, vocational/educational continuity

— Higher asparaginase tolerance than older adults

— Increased ALL risk (~20× general population)

— Higher treatment-related toxicity: mucositis, infections, methotrexate sensitivity

— Dose modifications and close monitoring; specialized protocols

— Often CRLF2 rearrangements (Ph-like biology)

— Males: sperm banking before any chemotherapy

— Females: oocyte/embryo cryopreservation if time allows; ovarian tissue cryopreservation as alternative; GnRH agonists adjunctively (data mixed)

— Discuss before first chemo dose — Step 3 emphasizes this as a quality-of-care marker

Pregnancy:

Adolescents and young adults (AYA, 15–39):

Down syndrome–associated ALL:

Fertility preservation (all reproductive-age patients):

Board pearl: Methotrexate is absolutely contraindicated in pregnancy (FDA category X equivalent) — known teratogen and abortifacient; substitute or defer until postpartum

Key distinction: AYA patients fare better on pediatric regimens than adult regimens — referral to AYA-experienced centers is a Step 3 systems-of-care answer

Complications and Adverse Outcomes

— Hyperuricemia, hyperkalemia, hyperphosphatemia, hypocalcemia, AKI

— Cairo-Bishop criteria for laboratory vs clinical TLS

— Management: aggressive IV fluids, rasburicase (high risk) or allopurinol (low risk), correct electrolytes, dialysis for refractory cases

— Do not alkalinize urine — promotes calcium phosphate precipitation

— ANC <500 + fever → blood cultures, urinalysis, CXR, then empiric cefepime, piperacillin-tazobactam, or meropenem within 1 hour

— Add vancomycin if line infection, skin/soft-tissue, hemodynamic instability, prior MRSA

— Add antifungal (caspofungin, voriconazole) if fever persists >4–7 days

— At diagnosis (~5–10%) or relapse — IT chemo escalation; sometimes cranial RT

— Cranial nerve palsies, headache, seizures

— Marrow, CNS, or testicular (sanctuary sites)

— Salvage with blinatumomab, inotuzumab, CAR-T, then allogeneic HSCT if response achieved

Tumor lysis syndrome (TLS):

Febrile neutropenia:

CNS leukemia:

Thrombosis: asparaginase-associated, especially cerebral venous sinus thrombosis — headache, seizures, focal deficits; treat with LMWH, antithrombin replacement, hold asparaginase

Pancreatitis: asparaginase — clinical + lipase; permanent discontinuation if severe

Hepatotoxicity, hyperbilirubinemia, VOD — especially after inotuzumab + HSCT

Cardiotoxicity: anthracycline-induced cardiomyopathy

Avascular necrosis of femoral/humeral heads from prolonged steroids, especially AYAs

Secondary malignancy: therapy-related AML/MDS years later

Relapse:

Post-transplant complications: GVHD, infections (CMV, fungal), graft failure

Step 3 management: Sudden severe headache + seizure in a patient on asparaginase → non-contrast head CT plus MRV/CTV to evaluate for cerebral venous sinus thrombosis, not just hemorrhage; start anticoagulation if confirmed and platelets supportable

Board pearl: Persistent fever despite broad-spectrum antibiotics on day 4–7 of neutropenia → add empiric antifungal coverage and obtain CT chest looking for invasive aspergillosis (halo sign)

When to Escalate Care — ICU, Consults, Inpatient Triage

— Hematology/oncology (primary)

— Bone marrow transplant team (HLA typing, donor search early)

— Reproductive endocrinology / fertility preservation

— Infectious disease if complex infection or HBV/HCV/HIV+

— Cardiology if baseline LVEF <50% or known cardiac disease

— Social work, psychiatry, palliative care (symptom + goals, not end-of-life only)

— Hemodynamic instability / septic shock

— Respiratory failure (mediastinal mass, pulmonary leukostasis, pneumonia, ARDS)

— Severe TLS with refractory hyperkalemia or AKI requiring CRRT

— DIC with active bleeding

— Severe CRS (grade ≥3) from blinatumomab or CAR-T — vasopressors, mechanical ventilation

— ICANS with seizures or depressed mental status

— Major intracranial event (sinus thrombosis with mass effect, hemorrhage)

— All Ph-like, KMT2A, hypodiploid, MRD-positive after induction

— Relapsed/refractory disease

— Any patient who may be a CAR-T candidate

— Maintenance phase (oral 6-MP/MTX, monthly vincristine/prednisone)

— Stable surveillance after consolidation

— Ambulatory blinatumomab infusion in selected stable patients

All newly diagnosed adult ALL is an inpatient admission, typically to a hematology/oncology service at a tertiary center with transplant capability

Immediate consults at diagnosis:

ICU triage criteria:

Transfer to transplant center for:

Airway emergency: large mediastinal mass + airway compromise — avoid supine positioning and deep sedation; involve anesthesia and thoracic surgery; consider rapid steroid initiation and emergent radiation

Outpatient management appropriate only for:

CCS pearl: On the CCS case, for a newly diagnosed adult ALL with WBC 80K and fever, your sequence is: admit to oncology floor → blood cultures and empiric cefepime → IVF + rasburicase → bone marrow biopsy + flow cytometry → HLA typing → fertility consult → start induction once cytogenetics returns and TKI added if Ph+

Step 3 management: Document goals of care and code status at admission for every newly diagnosed acute leukemia patient — induction mortality is real (~5% in fit adults, higher in elderly)

Key Differentials — Same-Category (Other Hematologic Malignancies)

— Distinguishing features: Auer rods on smear, MPO+ blasts, myeloid surface markers (CD13, CD33, CD117) on flow

— Different chemotherapy (7+3 cytarabine + anthracycline)

— APL (t(15;17)) is a subtype of AML — coagulopathy/DIC dominant, treat with ATRA + arsenic trioxide, hematologic emergency

— Prior CML history or splenomegaly, BCR::ABL1 positive — can mimic Ph+ ALL

— Treatment overlaps (TKI-based), but blast crisis carries worse prognosis

— Mature B-cell neoplasm — surface immunoglobulin positive, MYC translocation (t(8;14)), TdT negative

— "Starry sky" on histology

— Treated with intensive short-duration regimens (CODOX-M/IVAC or DA-EPOCH-R), not standard ALL protocols

— Same biology as ALL but <20% marrow blasts and nodal/mediastinal predominance

— Treated like ALL — same regimens

— Older adults, lymphocytosis with smudge cells, mature B-cell phenotype (CD5+, CD23+, CD19+, weak surface Ig)

— Indolent course — not confused with ALL pathologically but may be on the differential of lymphocytosis

— Mature B-cell, distinct immunophenotype (mantle: CD5+, cyclin D1+; hairy cell: CD11c+, CD25+, CD103+, BRAF V600E)

— <20% blasts, dysplasia in multiple lineages, older patients

— Transformation to AML possible

Acute myeloid leukemia (AML):

Chronic myeloid leukemia (CML) in lymphoid blast crisis:

Burkitt lymphoma/leukemia:

Lymphoblastic lymphoma:

Chronic lymphocytic leukemia (CLL):

Mantle cell, follicular, hairy cell leukemia:

Myelodysplastic syndrome with excess blasts:

Key distinction: Burkitt vs ALL — both are lymphoblastic in appearance but Burkitt is mature B (surface Ig+, TdT−) and requires Burkitt-specific therapy; misclassification leads to undertreatment

Board pearl: TdT positivity distinguishes lymphoblastic neoplasms (ALL, lymphoblastic lymphoma) from mature lymphoid malignancies (Burkitt, CLL, mantle cell)

Key Differentials — Other-Category Causes

— EBV infectious mononucleosis — atypical lymphocytes, lymphadenopathy, splenomegaly, but no blasts, positive monospot/EBV serology

— CMV mononucleosis — similar picture in immunocompetent

— Pertussis — marked lymphocytosis in adults

— Disseminated TB — pancytopenia, marrow involvement

— HIV acute seroconversion — lymphadenopathy, cytopenias

— Pancytopenia without blasts; hypocellular marrow (vs hypercellular in leukemia)

— Can be drug, viral, idiopathic; treat with immunosuppression or HSCT

— Pancytopenia, hypersegmented neutrophils, macrocytosis, elevated LDH and indirect bilirubin (ineffective erythropoiesis) — can mimic leukemia

— Resolves with vitamin replacement

— Isolated cytopenia without blasts or systemic features

— Leukoerythroblastic smear (nucleated RBCs, immature myeloid forms), teardrop cells; suggests marrow replacement

— Fever, splenomegaly, cytopenias, hyperferritinemia, hypertriglyceridemia, hypofibrinogenemia, hemophagocytosis on marrow

— Triggered by infection, malignancy (sometimes lymphoma), autoimmune disease

— Adult Still disease, SLE with cytopenias — fever, arthralgia, rash; bone marrow without blasts

— Chemotherapy, immunosuppressants, methimazole, sulfonamides — review meds carefully

— Lymphoma (Hodgkin, non-Hodgkin), thymoma, germ cell tumor, sarcoidosis

Severe infections mimicking leukemia:

Aplastic anemia:

Megaloblastic anemia (B12/folate deficiency):

Immune thrombocytopenia (ITP) / autoimmune cytopenias:

Bone marrow infiltration by solid tumor (metastatic carcinoma):

Hemophagocytic lymphohistiocytosis (HLH):

Rheumatologic disease:

Drug-induced cytopenias:

Mediastinal mass differential (mimicking T-ALL):

Step 3 management: Pancytopenia + hypercellular marrow with blasts = leukemia; pancytopenia + hypocellular marrow = aplastic anemia; pancytopenia + megaloblasts = B12/folate deficiency — these three patterns separate the differential quickly

Board pearl: A young adult with fever, lymphadenopathy, splenomegaly, and atypical lymphocytes (not blasts) — get EBV/CMV serology and monospot before assuming leukemia

Secondary Prevention, Discharge Medications, Long-Term Plan

— 6-mercaptopurine daily (oral)

— Methotrexate weekly (oral)

— Vincristine + prednisone monthly pulses (in many protocols)

— Ph+ patients: continue TKI (dasatinib/ponatinib) often indefinitely

— TMP-SMX for PJP through end of therapy and 3–6 months after

— Acyclovir for HSV/VZV during chemo and post-HSCT

— Fluoroquinolone during prolonged neutropenia (controversial; institution-dependent)

— Azole antifungal during neutropenia (caution with vincristine timing)

— HBV antiviral (entecavir/tenofovir) if HBV core Ab+

— No live vaccines during chemo (no MMR, varicella, zoster live, yellow fever)

— Inactivated influenza annually

— Pneumococcal (PCV20 or PCV15+PPSV23), Tdap, HPV per age

— Post-HSCT: full revaccination starting ~6–12 months after transplant

— Smoking cessation, alcohol moderation

— Avoid pregnancy during therapy and for ~6–12 months after; contraception counseling

— Sun protection — increased skin cancer risk after therapy/transplant

— Dental care — clearance before therapy to reduce sepsis risk

— Steroid-induced osteoporosis and AVN risk

— Calcium, vitamin D supplementation; DEXA scan; bisphosphonate if osteoporotic

Maintenance therapy (B-ALL and T-ALL, 2–3 years total from start of therapy):

Infection prophylaxis during and after intensive therapy:

Vaccinations:

Lifestyle counseling:

Bone health:

Cardiovascular surveillance: anthracycline-treated patients need periodic echocardiography

Fertility follow-up: sperm/oocyte assessment after recovery

Survivorship plan: structured handoff document listing cumulative anthracycline dose, RT exposure, transplant status, late-effect screening schedule

Board pearl: Live vaccines are contraindicated for at least 6 months post-chemotherapy and longer post-HSCT — a vaccinated household contact who received the oral polio or smallpox vaccine could transmit to the immunocompromised patient

Step 3 management: At each maintenance visit, monitor CBC for over- or under-dosing of 6-MP; target ANC 0.75–1.5 × 10⁹/L; dose-reduce 6-MP if on allopurinol (xanthine oxidase inhibition causes toxic 6-MP accumulation)

Follow-Up, Monitoring, Rehab and Counseling

— Daily CBC, CMP, coags during inpatient phase

— TLS labs q6–8h initially

— Daily exam: neuro, cardiopulmonary, line site, mucosa

— Blood cultures with each fever; surveillance cultures per institution

— CBC every 1–2 weeks initially, then monthly

— CMP monthly for hepatic/renal monitoring (6-MP, MTX)

— Adjust 6-MP and MTX doses to target ANC and absence of toxicity

— Monthly clinic visit; LP with IT chemo per protocol

— MRD assessment at end of induction, post-consolidation, periodically during maintenance (every 3 months ×2 years, then less frequently)

— Bone marrow biopsy at end of induction (day 28–35), end of consolidation, and at any clinical suspicion of relapse

— Rising MRD or cytopenia → re-stage marrow

— CBC every 1–3 months in year 1, then quarterly, then annually

— Annual physical exam, focused on lymphadenopathy, organomegaly, neuro

— Cardiac echo every 1–2 years if anthracycline exposure

— DEXA, lipids, fasting glucose (steroid-related metabolic effects)

— Skin and dermatologic screening post-transplant

— Endocrine: thyroid function, gonadal function annually

— Pulmonary function tests post-HSCT

— Cancer-related fatigue: graded exercise program, physical therapy

— Cognitive complaints ("chemo brain"): neuropsych referral if persistent

— Mental health: depression, anxiety, PTSD common — screen at every visit, refer to psycho-oncology

— Nutrition counseling — sarcopenia, weight changes

— Return to work/school planning with occupational therapy

— Sexual health and intimacy counseling

— Support groups, peer mentoring, financial navigation

— Maintenance non-adherence (especially 6-MP) drives relapse — counseling, pill organizers, app reminders

During induction/consolidation:

During maintenance (outpatient):

Disease surveillance:

Post-treatment surveillance (years 1–5+):

Rehabilitation and counseling:

Adherence emphasis:

Board pearl: Detectable MRD during maintenance — even at very low levels (10⁻⁴) — predicts overt relapse and should trigger reinduction with blinatumomab/inotuzumab and transplant evaluation, not "watch and wait"

Ethical, Legal, and Patient Safety Considerations

— Discuss induction mortality (~5% in young fit adults, up to 20–30% in elderly), long treatment duration (2–3 years), sterility risk, secondary malignancy risk, transplant possibility

— Document capacity assessment in patients with confusion from CNS leukemia or severe anemia before they consent — if incapacitated, identify surrogate per state hierarchy

— ASCO guidelines mandate fertility counseling before initiating gonadotoxic therapy; failure to offer constitutes a quality-of-care lapse

— Time pressure may force decision in 24–48 hours — document the discussion

— First-trimester ALL patients face a wrenching choice — provide non-directive counseling, ethics consult, and respect autonomy; institutional policies vary

— Introduce early palliative care at diagnosis — improves symptom control and quality of life without compromising disease-directed therapy

— Address code status during admission; revisit after each major clinical change

— Adult ALL outcomes lag pediatric outcomes partly due to lower trial enrollment — actively offer trial participation; document discussion

— Discharge from induction → outpatient consolidation: medication reconciliation (TKI, prophylactic antimicrobials, 6-MP), follow-up within 1 week, clear instructions for fever (return immediately)

— Transfer to transplant center: standardized handoff (cytogenetics, MRD, transfusion history, infection history, organ function)

— Maintenance handoff to community oncologist: document protocol, total cumulative doses, late-effect screening plan

— Vincristine intrathecal administration is fatal — vincristine is IV only; institutions require dual checks and labeled syringes (Joint Commission sentinel event)

— Methotrexate dosing errors (daily vs weekly) — daily dosing in maintenance is correct but in other contexts (RA) weekly dosing applies

— Rasburicase in G6PD deficiency causes hemolysis — screen high-risk populations

— Therapy-related secondary malignancies reportable to cancer registries

— Adverse drug reactions to FDA MedWatch

Informed consent for induction:

Fertility preservation as standard of care:

Pregnancy decisions:

Goals of care and palliative care integration:

Clinical trial enrollment:

Transitions of care — high-risk handoffs:

Patient safety pitfalls:

Mandatory reporting:

Board pearl: "Intrathecal vincristine = death" is one of the most reliable patient-safety vignettes — the answer is always institutional dual-verification protocols and clear labeling

High-Yield Associations and Rapid-Fire Facts

B-ALL markers: CD19, CD22, CD79a, TdT, CD10 (common B-ALL)

T-ALL markers: cytoplasmic CD3, CD7, TdT; often presents with mediastinal mass in young males

Ph+ ALL = t(9;22), BCR::ABL1 → add TKI (dasatinib/ponatinib preferred over imatinib in ALL)

Ph-like ALL = same expression profile, no BCR::ABL1; often CRLF2 rearrangement; targetable kinase fusions (JAK2, ABL-class)

MLL/KMT2A rearrangement = poor prognosis; common in infant ALL and therapy-related

Hypodiploidy (<44 chromosomes) = poor prognosis

Hyperdiploidy (>50) and t(12;21) ETV6-RUNX1 = good prognosis (mostly pediatric)

TdT is the hallmark of lymphoblastic neoplasms (vs mature lymphoid)

PAS-positive, MPO-negative blasts = ALL; MPO-positive with Auer rods = AML

Down syndrome → 20× ALL risk; CRLF2+ Ph-like biology common

Burkitt ≠ ALL — surface Ig+, TdT−, MYC translocation, "starry sky"; treated with CODOX-M/IVAC, not ALL regimens

Pediatric-inspired regimens beat traditional adult regimens in AYAs

MRD-negative after induction = single best prognostic factor

Blinatumomab (CD19/CD3 BiTE) — MRD eradication, R/R B-ALL; CRS + neurotoxicity

Inotuzumab ozogamicin (anti-CD22 ADC) — R/R B-ALL; VOD/SOS risk, especially pre-HSCT

CAR-T (tisa-cel, brexu-cel) — R/R B-ALL; CRS (tocilizumab), ICANS (steroids)

Asparaginase — thrombosis, pancreatitis, hepatotoxicity, hyperglycemia, hypofibrinogenemia

6-MP + allopurinol = toxicity (xanthine oxidase blocks 6-MP metabolism) → dose-reduce 6-MP by 75%

TPMT/NUDT15 deficiency + standard 6-MP = lethal myelosuppression

Rasburicase contraindicated in G6PD deficiency (hemolysis)

No urinary alkalinization in TLS — causes calcium phosphate precipitation

Vincristine IT = fatal — always IV only

CNS prophylaxis is mandatory in every ALL patient (intrathecal chemo)

Live vaccines contraindicated during chemo and ≥6 months after

Avoid azole antifungals concurrent with vincristine — neurotoxicity

Board pearl: A young male, mediastinal mass, cytopenias, blasts with cytoplasmic CD3 = T-ALL — induction includes pediatric-inspired chemo and CNS prophylaxis; consider nelarabine in relapsed T-ALL

Board Question Stem Patterns

Stem 1 — newly diagnosed Ph+ adult B-ALL: 45-year-old with fatigue, petechiae, WBC 80K with blasts; flow shows CD19+, CD10+, TdT+; cytogenetics t(9;22). Best next step: induction chemotherapy plus dasatinib (or ponatinib); HLA typing; CNS prophylaxis

Stem 2 — TLS prophylaxis selection: patient with WBC 200K, LDH 4000, creatinine 2.0, uric acid 12. Answer: rasburicase + aggressive IV hydration, monitor electrolytes; not allopurinol (insufficient for high risk); screen for G6PD if at risk

Stem 3 — vincristine + azole interaction: patient on hyperCVAD develops severe constipation/ileus and worsening neuropathy after voriconazole started. Answer: discontinue azole (CYP3A4 inhibition increases vincristine); switch to echinocandin

Stem 4 — asparaginase complication: young adult on pegaspargase develops sudden headache and left-sided weakness. Answer: MR venography for cerebral venous sinus thrombosis; treat with LMWH and antithrombin repletion

Stem 5 — MRD-positive after induction: B-ALL patient achieves morphologic CR but MRD by flow cytometry at 0.05%. Answer: blinatumomab to eradicate MRD, then allogeneic HSCT

Stem 6 — VOD after inotuzumab + transplant: RUQ pain, weight gain, hyperbilirubinemia, ascites 2 weeks post-HSCT in patient who received inotuzumab. Answer: defibrotide

Stem 7 — T-ALL with mediastinal mass: young man with stridor, facial plethora, mediastinal mass. Answer: avoid supine positioning and deep sedation; emergent steroids; tissue diagnosis; treat as T-ALL

Stem 8 — fertility preservation: newly diagnosed 28-year-old woman with ALL. Answer: offer oocyte/embryo cryopreservation before initiating chemo

Stem 9 — elderly Ph+ ALL: 72-year-old with ECOG 2 and Ph+ B-ALL. Answer: TKI (dasatinib or ponatinib) + blinatumomab + steroids (chemo-free induction)

Stem 10 — 6-MP toxicity: patient on maintenance develops profound pancytopenia after starting allopurinol. Answer: reduce 6-MP dose by 75% (xanthine oxidase interaction); check TPMT/NUDT15 if recurrent

Stem 11 — pregnancy in first trimester: newly diagnosed ALL at 8 weeks gestation. Answer: non-directive counseling including therapeutic termination; if continuing, defer methotrexate; ethics + MFM consult

Stem 12 — neutropenic fever: ANC 200, temp 38.5°C. Answer: blood cultures and empiric cefepime (or pip-tazo) within 1 hour

Board pearl: When the stem says "Philadelphia chromosome positive" — the answer always includes a TKI, never chemo alone

One-Line Recap

Adult ALL is a hematologic emergency in which prompt risk stratification, MRD-driven multi-phase therapy (induction → consolidation → 2–3 years maintenance), CNS prophylaxis, TKI addition for Ph+ disease, and immunotherapy (blinatumomab, inotuzumab, CAR-T) for MRD-positive or relapsed disease — supported by tumor lysis prevention, infection prophylaxis, and early transplant evaluation in high-risk subgroups — define modern management.

Diagnosis: ≥20% lymphoblasts on marrow + flow cytometry (B-ALL: CD19/22/79a/TdT; T-ALL: cyto CD3/CD7/TdT); always test BCR::ABL1 and full cytogenetics/molecular panel

Treatment backbone: induction (vincristine, anthracycline, steroids, asparaginase, ± cyclophosphamide) → consolidation (high-dose MTX, cytarabine) → CNS prophylaxis (intrathecal chemo every phase) → maintenance (6-MP daily, MTX weekly, vincristine/prednisone pulses, 2–3 years); add TKI through maintenance for Ph+; pediatric-inspired regimens preferred for AYA ≤40

Critical safety items: rasburicase for high-risk TLS (not in G6PD deficiency), no urinary alkalinization, dose-reduce 6-MP with allopurinol, screen TPMT/NUDT15, avoid azoles concurrent with vincristine, vincristine IV only (never IT), live vaccines contraindicated, fertility preservation before chemo, HLA typing at diagnosis

Prognostic and management triggers: MRD positivity after induction drives blinatumomab + allogeneic HSCT; Ph-like, KMT2A, hypodiploidy = high risk → transplant in CR1; relapsed/refractory disease → inotuzumab, blinatumomab, or CAR-T; elderly/unfit Ph+ → chemo-free TKI + blinatumomab + steroids regimen

Step 3 management: Every newly diagnosed adult ALL gets immediate inpatient admission, tumor lysis prophylaxis, neutropenic fever protocol readiness, early hematology/transplant/fertility/palliative care consults, and a documented MRD-driven roadmap from day one