42  Oncological Emergencies

Published

June 20, 2025

42.1 Introduction

Oncological emergencies are acute, potentially life-threatening conditions that affect patients with cancer, either due to the malignancy itself or as complications arising from its treatment. Early recognition and prompt intervention are crucial in preventing morbidity and mortality. Understanding these emergencies is essential for all healthcare professionals, particularly in resource-limited settings like Ghana, where delays in cancer diagnosis and treatment are prevalent. Oncological emergencies are generally classified into three categories:

  1. Metabolic Emergencies
  2. Hematological Emergencies
  3. Structural/Mechanical Emergencies

42.2 Metabolic Emergencies

42.2.1 Tumor Lysis Syndrome (TLS)

Definition: A life-threatening condition that occurs when massive tumor cell lysis releases intracellular contents (potassium, phosphate, uric acid) into the bloodstream, leading to acute kidney injury and cardiac arrhythmias.

Common Causes:

  • High-grade lymphomas (especially Burkitt lymphoma)
  • Acute leukemias (e.g., ALL)
  • Solid tumors with high tumor burden after chemotherapy

Clinical Features:

  • Nausea and vomiting
  • Lethargy
  • Muscle cramps
  • Seizures
  • Oliguria or anuria
  • Arrhythmias

Diagnostic Criteria (Cairo-Bishop):

Laboratory TLS involves ≥2 of the following:

  • Uric acid > 476 μmol/L
  • Potassium > 6.0 mmol/L
  • Phosphate > 1.45 mmol/L
  • Calcium < 1.75 mmol/L

Management:

  • Aggressive IV hydratio
  • Allopurinol or rasburicase (rasburicase preferred)
  • Correction of electrolyte imbalances
  • Dialysis for refractory cases

42.2.2 Hypercalcemia of Malignancy

Definition: Elevated serum calcium level (usually >2.6 mmol/L) due to malignancy.

Common Causes:

  • Breast cancer
  • Multiple myeloma
  • Lung cancer
  • Renal cell carcinoma
  • Parathyroid hormone-related protein (PTHrP) production

Clinical Features:

  • Nausea, vomiting
  • Polyuria, polydipsia
  • Constipation
  • Confusion, coma
  • Shortened QT interval

Management:

  • IV hydration with normal saline
  • Bisphosphonates (e.g., zoledronic acid)
  • Calcitonin for rapid reduction
  • Dialysis in severe cases

42.2.3 Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

Definition: Excessive release of antidiuretic hormone leads to water retention and hyponatremia.

Common Causes:

  • Small cell lung carcinoma
  • CNS tumors

Clinical Features:

  • Headache
  • Confusion
  • Seizures
  • Coma

Management:

  • Fluid restriction
  • Hypertonic saline (3%) in severe hyponatremia
  • Demeclocycline or vasopressin receptor antagonists in chronic cases

42.3 Hematological Emergencies

42.3.1 Febrile Neutropenia

Definition: Fever (>38°C) with absolute neutrophil count (ANC) < 0.5 × 10⁹/L in a cancer patient.

Causes:

  • Chemotherapy-induced bone marrow suppression

Clinical Features:

  • Fever (often the only sign)
  • Signs of infection may be subtle

Management:

  • Broad-spectrum antibiotics within 1 hour (e.g., cefepime, piperacillin-tazobactam)
  • Risk stratification (MASCC score)
  • G-CSF in selected cases
  • Isolate and monitor closely

42.3.2 Disseminated Intravascular Coagulation (DIC)

Definition: Widespread activation of the coagulation system leads to the consumption of clotting factors and platelets, resulting in bleeding and thrombosis.

Common Causes:

  • Acute promyelocytic leukemia (APL)
  • Metastatic cancers

Clinical Features:

  • Bleeding (petechiae, ecchymosis, mucosal bleeding)
  • Thrombosis
  • Organ dysfunction

Laboratory Findings:

  • Prolonged PT, aPTT
  • Low fibrinogen
  • Elevated D-dimer
  • Thrombocytopenia

Management:

  • Treat underlying cause (e.g., ATRA for APL)
  • Transfusions (platelets, FFP)
  • Heparin in cases with thrombosis

42.3.3 Hyperviscosity Syndrome

Definition: Increased blood viscosity due to elevated cellular or protein components.

Common Causes:

  • Waldenström’s macroglobulinemia (IgM)
  • Multiple myeloma
  • Leukemia with very high WBC

Clinical Features:

  • Visual disturbances
  • Headache
  • Mucosal bleeding
  • Confusion
  • Heart failure

Management:

  • Plasmapheresis
  • Hydration
  • Treat underlying cancer

42.4 Structural/Mechanical Emergencies

42.4.1 Superior Vena Cava (SVC) Syndrome

Definition:

Obstruction of blood flow through the superior vena cava, commonly due to external compression by tumors.

Common Causes:

  • Small cell lung cancer
  • Non-Hodgkin lymphoma
  • Metastatic mediastinal tumors

Clinical Features:

  • Facial and upper limb swelling
  • Dyspnea
  • Distended neck veins
  • Cyanosis
  • Cough and hoarseness

Diagnosis:

  • Chest X-ray: mediastinal widening
  • CT scan: to confirm compression
  • Biopsy of mass (if unknown etiology)

Management:

  • Elevate the head
  • Steroids to reduce edema
  • Radiotherapy or chemotherapy, depending on etiology
  • Stenting in severe cases

42.4.2 Spinal Cord Compression

Definition:

Compression of the spinal cord due to a tumor, leading to neurological deficits.

Common Causes:

  • Breast, prostate, and lung cancers
  • Lymphomas
  • Myeloma

Clinical Features:

  • Back pain (worsened by lying down)
  • Weakness in limbs
  • Sensory loss
  • Bladder/bowel incontinence

Diagnosis:

  • MRI spine (preferred)
  • Neurological exam

Management:

  • High-dose corticosteroids (e.g., dexamethasone)
  • Emergency radiotherapy or surgery
  • Rehabilitation

42.4.3 Pericardial Tamponade

Definition:

Accumulation of fluid in the pericardial sac impairs cardiac output.

Common Causes:

  • Lung and breast cancers
  • Lymphomas
  • Metastatic cancers

Clinical Features:

  • Dyspnea
  • Chest discomfort
  • Hypotension
  • Elevated JVP
  • Muffled heart sounds (Beck’s triad)

Diagnosis:

  • Echocardiography: diagnostic
  • ECG: low-voltage QRS or electrical alternans

Management:

  • Urgent pericardiocentesis
  • Fluid resuscitation
  • Treat underlying malignancy

42.4.4 Intestinal Obstruction

Definition: Partial or complete blockage of the bowel lumen.

Common Causes:

  • Colorectal cancer
  • Ovarian cancer
  • Gastric cance
  • Peritoneal metastases

Clinical Features:

  • Abdominal distension
  • Vomiting
  • Constipation
  • Colicky abdominal pain

Diagnosis:

  • Abdominal X-ray or CT scan

Management:

  • Nasogastric decompression
  • IV fluids and electrolytes
  • Surgery if obstruction is complete or complications arise
  • Stenting in selected cases

42.5 Increased Intracranial Pressure (ICP)

Causes:

  • Brain metastases (lung, breast, melanoma)
  • Primary CNS tumors
  • Leptomeningeal disease

Clinical Features:

  • Headache
  • Vomiting (projectile)
  • Seizures
  • Altered mental status
  • Papilledema

Diagnosis:

  • Brain imaging (CT or MRI)

Management:

  • Corticosteroids (dexamethasone)
  • Mannitol for acute relief
  • Neurosurgical consultation
  • Radiotherapy/chemotherapy, depending on the cause

42.6 Approach to the Patient with an Oncological Emergency

1. ABCDE Approach

  • Airway: Ensure patency, especially in patients with superior vena cava syndrome or airway tumors.
  • Breathing: Provide oxygen if hypoxic.
  • Circulation: Monitor for signs of shock (e.g., tamponade, disseminated intravascular coagulation).
  • Disability: Assess for neurological compromise (e.g., spinal cord compression, raised ICP).
  • Exposure: Full examination to identify other signs (e.g., petechiae, masses).

2. Laboratory and Imaging

  • CBC, U&E, calcium, phosphate, uric acid
  • Coagulation profile
  • ECG and echocardiography
  • CT/MRI depending on clinical suspicion

3. Specialist Referral

  • Oncology, surgery, radiotherapy, hematology, or palliative care, depending on diagnosis.

Challenges in the Ghanaian Setting

  • Limited access to imaging (CT/MRI)
  • Delays in diagnosis and referral
  • Shortage of oncologists and hematologists
  • Limited availability of drugs (e.g., rasburicase, bisphosphonates)
  • Inadequate supportive care facilities (ICU, dialysis)

Summary Table: Common Oncological Emergencies

Emergency Main Feature Key Management
Tumor Lysis Syndrome Electrolyte disturbances, renal failure Hydration, rasburicase
Hypercalcemia Confusion, constipation Hydration, bisphosphonate
SIAD Hyponatremia, confusion Fluid restriction, hypertonic saline
Febrile Neutropenia Fever in neutropenia Broad-spectrum antibiotics
DIC Bleeding, low platelets Treat the cause, transfusion
SVC Syndrome Facial swelling, JVP Steroids, radiotherapy
Spinal Cord Compression Back pain, limb weakness Steroids, MRI, radiotherapy
Tamponade Hypotension, JVP Pericardiocentesis
Bowel Obstruction Abdominal pain, vomiting NG tube, fluids, and surgery
Increased ICP Headache, vomiting Steroids, mannitol, imaging

Conclusion

Oncological emergencies require prompt identification and urgent management to prevent irreversible complications or death. In Ghana, with rising cancer incidence and limited resources, medical students and junior doctors must be adept at recognizing early signs and initiating life-saving interventions. Close collaboration with oncology, radiology, and surgical teams is essential for optimal outcomes.