Oncologic Emergencies

Hyperleukocytosis: WBC >100,000/μL.
Leukostasis: Hyperleukocytosis + symptoms of impaired end organ perfusion.

• Seen mainly in AML; rare in CML/CLL unless significant increase in peripheral blasts.

Pathophysiology

• Rigid leukemic blasts → microvascular plugging → ↓ flow, ↑ viscosity → endothelial injury, cytokine release → hemorrhage, local hypoxemia within tissues (most notable lungs and CNS).

Presentation

• Common: headache, vision changes, dizziness, dyspnea, hypoxia, fever.
• Uncommon: abdominal pain, priapism, limb pain.

Evaluation

• CBC w/diff, smear, DIC/TLS labs, troponin.
• CT head (if neuro symptoms).
• CXR or chest CT.
• ABG PaO₂ may be falsely low → rely on SpO₂.

Management

• Call Hematology.
• Transfer/admit to ICU.
• Emergent cytoreduction.
• Consider leukapheresis (controversial).
• Hydroxyurea/chemo per Hematology.
• Avoid PRBCs until leukostasis treated (↑ viscosity).

Pathophysiology

• High cell turnover → release of intracellular contents → hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia.

Presentation

• Clinical TLS = ≥2 lab abnormalities + complication.
• Highest risk after starting chemotherapy, but can occur spontaneously.
  Symptoms: hypotension, AKI, arrhythmias, GI symptoms, seizures, lethargy, sudden death.  Lab criteria= uric acid ≥8, Ca ≤7, K ≥6, PO₄ ≥4.5 or 25% change from baseline in these values.

Risk Stratification

• Cairo-Bishop framework; see tool here.

Management

Prevention:

• High risk: q4–6h labs, IVF ± loop diuretics if volume overloaded, allopurinol ± Rasburicase.
• Intermediate: q8h labs, IVF, allopurinol.
• Low: daily labs, IVF.
• IVF goal: UOP 2 mL/kg/hr.
• Allopurinol: 300 mg PO BID for CrCl > 20 mL/min, UpToDate renal dosing if lower.
• Rasburicase: for uric acid >8; avoid in G6PD deficiency (send G6PD, discuss with
  fellow/attending).

Treatment:

• K+ > 5.5: STAT EKG, lokelma 10g TID, 10 U insulin+ 1 amp D50.
• If EKG changes-> calcium gluconate and D5W at 100 mL/hr with repeat BG in 1 hr.
• Uric acid > 8 with 25% change from baseline: page hematology fellow to discuss
  rasburicase.
• PO4 > 4.5 with 25% change from baseline: start/↑ phos binder (sevelamer).
• IV calcium: do not administer unless symptomatic AND hyperphosphatemia is corrected.
• Hemodialysis: consider Nephrology consultation early if worsening Cr, refractory
  symptoms, or refractory electrolyte abnormalities.

Background

• SVC obstruction -> upstream congestion in head, neck, upper extremities.
• Usually due to mediastinal mass or thrombosis.
• Associated malignancies: lung cancer (NSCLC or SCLC), Non-Hodgkin or Hodgkin lymphoma, mediastinal germ cell tumors, thymic malignancies.

Presentation 

• Head fullness (worse when leaning forward or lying down), dyspnea, stridor, hoarseness, cough. Facial/neck swelling, distended veins, upper extremity edema, lymphadenopathy, papilledema, and plethora.

Evaluation

• CXR: mass, mediastinal widening, or pleural effusion.
• Contrast CT ± venography to assess clot and stenting.
• MRI/MRV if feasible.
• Non-malignant causes: post-radiation fibrosis, fibrosing mediastinitis, central AV fistula.

Management

• Secure airway if needed; elevate head.
• Thrombosis: remove lines, consider anticoagulation.
• Tumor type guides therapy: Stat/Urgent Consults:
• Interventional radiology: possible stenting/dilatation (Fastest).
• Radiation oncology: radiation therapy (Takes days to weeks to work).
• Medical oncology: help with diagnosis and chemotherapy (Fast if highly chemo-responsive cancer).
• Interventional pulmonology: tissue dx.

Background

• Common malignancies: multiple myeloma, lymphoma (Hodgkin and NHL); lung, breast, prostate, and renal cell.

Presentation 

• Back pain, progressive motor, or sensory deficits (saddle anesthesia, numbness, paresthesia).
• Cauda equina syndrome: bowel/bladder incontinence, ataxia.

Evaluation

• Neuro exam (identify sensory level).
• Back pain exacerbated by movement = mechanically unstable spine until proven otherwise (requires surgical evaluation and potential stabilization).
• Labs (if no known cancer): CBC, CMP, SPEP, ± PSA (males).
• Bladder U/S if retention suspected.
• MRI whole spine w/wo contrast (CT myelogram if MRI not possible).

Management 

• Immediate high dose steroids: dexamethasone 10mg IV x1 followed by 4mg PO or IV q6h.
• Stat/urgent consults:
• Spine Team (Neurosurgery and Orthopedics alternate pager): consult early, ask for an operative plan ASAP. Affects other possible interventions.
• Radiation oncology: rare case where overnight radiation may be necessary. Requires patient lie flat for a CT simulation (rad onc orders this); rad onc cannot proceed until Spine surgery decides about operation.
• Medical oncology: help with diagnosis and chemotherapy.
• Frequent neuro-vascular checks and close monitoring.

Presentation

• Variable--consider brain mets in any cancer pt with neurologic or behavioral changes.

Evaluation

• STAT CT if concerned for stroke or elevated ICP.
• MRI with contrast: most sensitive, can differentiate metastases vs. other.
  • Suggestive features: multiple lesions, location, circumscribed margins, vasogenic edema, contrast enhancement.
• If no known primary : consider CT C/A/P ± PET.
• Biopsy with histopathology and IHC: if unclear diagnosis or only single lesion present.

Management

• If severe HA, N/V, focal neuro deficits: Dexamethasone 10mg IV x1 followed by 4mg IV or PO q6h.
• Stat/urgent consults:
  • Neurosurgery: diagnostic/therapeutic intervention. Note they will need a tissue diagnosis ASAP if not known; affects operative plan.
  • Radiation oncology: also needs tissue diagnosis. Coordinate with neurosurgery about timing of surgery versus radiation. Patient must be able to lie flat.
  • Medical oncology: diagnosis and systemic therapy.
• Regular neuro-vascular checks and close monitoring.
• Do not perform LP without neurology input.