Step 2 CK · Internal Medicine · Hematology/Oncology

Oncologic Emergencies

Name: Oncologic Emergencies
Creator: Veli Bakalov, MD

When the clock is the diagnosis: act before the scan, before the culture

Hematology/Oncology·General Oncology·4 min read·9 high-yield points·Reviewed by Veli Bakalov, MD @HemeOncBuddy

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Febrile neutropenia = ANC <500 (or expected to fall below 500 within 48 hours) plus a single temp ≥38.3 °C or ≥38.0 °C sustained for 1 hour → antipseudomonal β-lactam (cefepime, piperacillin-tazobactam, meropenem) within 60 minutes; never wait for cultures.
Add vancomycin only for line/skin/soft-tissue infection, hemodynamic instability, pneumonia, or known MRSA; ceftriaxone is wrong because it lacks Pseudomonas coverage.
Hypercalcemia of malignancy is usually humoral PTHrP (squamous lung and head-neck, renal, bladder) with suppressed PTH; osteolytic in myeloma and breast; 1,25-vitamin D in lymphoma.
Hypercalcemia sequence: aggressive IV saline first → calcitonin (fast, tachyphylaxis ~48 h) → zoledronic acid (durable in 2–4 days); denosumab if refractory or in renal failure; no loop diuretic unless overloaded.
Cord compression (back pain worse lying down, then weakness and a sensory level): IV dexamethasone immediately, then urgent whole-spine MRI, then radiation or surgery.
SVC syndrome: facial and arm swelling, plethora, distended neck and chest-wall veins (lung cancer, NHL, thymoma, catheter thrombosis) → contrast CT; treat the cause, stent if severe.
Hyperviscosity (IgM/Waldenström: bleeding, blurred vision, confusion) → plasmapheresis; leukostasis (blasts >100,000, usually AML) → leukapheresis, hydroxyurea, chemotherapy; do NOT transfuse red cells first.
Tumor lysis: high K, phosphate, and uric acid with low calcium → IV fluids plus rasburicase (high risk; check G6PD first) or allopurinol, no urine alkalinization; give calcium only if symptomatic.
Malignant pericardial effusion can cause tamponade (Beck triad, pulsus paradoxus, electrical alternans) → urgent pericardiocentesis.

The principle: treat first, confirm second

The clock is the diagnosis. In oncologic emergencies the correct first move often comes before definitive imaging or culture results: antibiotics before culture results (febrile neutropenia), dexamethasone before the MRI (cord compression), saline before the bisphosphonate (hypercalcemia), and apheresis before treating the clone (hyperviscosity, leukostasis). Time-to-treatment drives outcome.

First moves in oncologic emergencies

Emergency	Recognize	First action	Avoid
Febrile neutropenia	ANC <500 plus fever ≥38.3 °C	Antipseudomonal β-lactam within 1 hour	Waiting for cultures
Hypercalcemia	Confusion, dehydration, suppressed PTH	Aggressive IV isotonic saline	Loop diuretics unless overloaded
Cord compression	Back pain plus weakness or a sensory level	IV dexamethasone, then whole-spine MRI	Delaying steroids for imaging
Tumor lysis	High K, phosphate, uric acid; low calcium	IV fluids plus rasburicase or allopurinol	Calcium for asymptomatic hypocalcemia
Hyperviscosity, leukostasis	Bleeding, visual change, confusion, hypoxia	Plasmapheresis or leukapheresis	Red cell transfusion
Pericardial tamponade	Beck triad, pulsus paradoxus	Urgent pericardiocentesis	Delaying drainage

Febrile neutropenia

ANC <500or expected to fall below 500 within 48 hours

38.3 °Csingle temperature (or 38.0 °C sustained for 1 hour)

≤60 minto the first antibiotic dose

Occult infection. Neutropenia blunts the usual signs of inflammation (little pus, minimal infiltrate, scant pyuria), so fever may be the only clue. Draw blood cultures, including from any central line, but do not delay treatment. Avoid rectal examinations and rectal temperatures.

Empiric antipseudomonal monotherapy. Give cefepime, piperacillin-tazobactam, or a carbapenem (meropenem) within 60 minutes. Pseudomonas coverage is the non-negotiable core, which is why ceftriaxone is inadequate. Add vancomycin only for suspected line, skin, or soft-tissue infection, hemodynamic instability, pneumonia, or known MRSA. Fever persisting beyond 4–7 days of antibiotics prompts empiric antifungal therapy; carefully selected low-risk patients may be treated as outpatients with oral ciprofloxacin plus amoxicillin-clavulanate.

Metabolic emergencies: hypercalcemia and tumor lysis

Hypercalcemia of malignancy is most often humoral, via PTHrP, and native PTH is low or suppressed, the key contrast with primary hyperparathyroidism. Symptoms are stones, bones, groans, and psychiatric overtones, with a short QT interval and a polyuria-driven dehydration that worsens the hypercalcemia.

Three mechanisms of hypercalcemia of malignancy

Mechanism	Typical tumors	Labs
Humoral (PTHrP), most common	Squamous cell lung and head and neck, renal, bladder	High PTHrP, low PTH
Osteolytic	Myeloma, breast	Low PTH; lytic lesions
1,25-vitamin D production	Lymphoma	High calcitriol, low PTH

IV isotonic salineNow: rehydrates and drives calciuresis.
CalcitoninFast bridge; tachyphylaxis by ~48 hours.
IV bisphosphonateZoledronic acid; durable effect in 2–4 days.
DenosumabIf bisphosphonate-refractory or in renal failure.

Hypercalcemia sequence: saline (now) → calcitonin (bridge) → zoledronate (durable)

Adjuncts. Avoid loop diuretics unless the patient is volume-overloaded. Glucocorticoids help vitamin D–mediated (lymphoma) hypercalcemia, and dialysis is reserved for severe, refractory cases with renal failure.

Tumor lysis syndrome follows treatment of bulky, high-turnover tumors: hyperkalemia, hyperphosphatemia, hyperuricemia, and hypocalcemia (three highs, one low), driving arrhythmia and acute kidney injury. Hydrate hard and give rasburicase (high risk) or allopurinol; check G6PD before rasburicase, which causes hemolysis and methemoglobinemia in G6PD deficiency. Urine alkalinization is no longer recommended. Treat hyperkalemia urgently; give calcium only for symptomatic hypocalcemia or cardiac effects, because calcium given into a high phosphate precipitates. Refractory cases need dialysis.

Compressive emergencies: cord, SVC, and effusions

Malignant epidural spinal cord compression starts with progressive back pain (worse when recumbent or at night), then weakness, a sensory level, and late bowel and bladder dysfunction such as urinary retention. The thoracic spine is most often involved; common primaries are prostate, breast, lung, and myeloma. Ambulatory status at diagnosis predicts the outcome.

Back pain plus weaknessSensory level, urinary retention.
IV dexamethasone nowOn clinical suspicion; do not wait for imaging.
Urgent whole-spine MRIThe gold standard.
Radiation or surgeryRadiation oncology and neurosurgery decompress.

Cord compression order of operations

Do not delay steroids for imaging: neurologic recovery is time-dependent.

Superior vena cava syndrome. Obstruction causes facial, neck, and upper-extremity swelling, plethora, distended neck and chest-wall veins, and dyspnea worse when bending forward. Causes include small cell and squamous lung cancer, non-Hodgkin lymphoma, thymoma, and indwelling-catheter thrombosis. Diagnose with contrast CT and, when the patient is stable, obtain tissue before treating; then treat the cause (radiation or chemotherapy for a tumor; anticoagulation and catheter removal for catheter thrombosis) and stent if severe. Stridor or cerebral edema warrants emergent stenting.

Malignant effusions. Pleural effusions (lung, breast) cause dyspnea and are drained by thoracentesis; recurrence is managed with pleurodesis or an indwelling pleural catheter. Pericardial effusions can produce cardiac tamponade, with Beck triad (hypotension, distended neck veins, muffled heart sounds), pulsus paradoxus, and electrical alternans, requiring urgent pericardiocentesis. Malignant effusions are typically exudative with malignant cytology.

Viscosity emergencies: hyperviscosity and leukostasis

Hyperviscosity syndrome vs leukostasis

Feature	Hyperviscosity syndrome	Leukostasis
Cause	Paraprotein, usually IgM from Waldenström (also myeloma)	Hyperleukocytosis: blasts >100,000/μL, usually AML
Findings	Mucosal bleeding, visual changes (dilated "sausage-link" retinal veins), headache, confusion, vertigo	Lungs: dyspnea, hypoxia; brain: headache, confusion, visual changes
Urgent treatment	Plasmapheresis to remove the paraprotein, then treat the clone	Cytoreduction: leukapheresis, hydroxyurea, induction chemotherapy

Why IgM? Waldenström macroglobulinemia is a lymphoplasmacytic lymphoma secreting pentameric IgM (MYD88 mutation); the large molecule stays in the vessels and thickens the blood.

In both syndromes, transfusing red cells first raises whole-blood viscosity and worsens sludging; remove the protein or cytoreduce instead.