AOCNP Oncologic Emergencies 4 — Questions and Answers
Question 1: A patient with small cell lung cancer presents with hyponatremia (Na 118 mEq/L), concentrated urine, and euvolemia. Which oncologic emergency is most likely?
- Adrenal crisis
- Syndrome of inappropriate antidiuretic hormone (SIADH) (Correct answer)
- Cerebral salt wasting
- Tumor lysis syndrome
Correct answer: Syndrome of inappropriate antidiuretic hormone (SIADH)
SIADH is a common paraneoplastic complication of small cell lung cancer presenting with euvolemic hyponatremia and urine osmolality inappropriately elevated relative to serum.
Question 2: Which of the following is the FIRST-LINE treatment for malignant spinal cord compression (MSCC) once the diagnosis is confirmed?
- Emergent radiation therapy
- High-dose corticosteroids (dexamethasone) (Correct answer)
- Surgical decompression
- IV bisphosphonate therapy
Correct answer: High-dose corticosteroids (dexamethasone)
High-dose dexamethasone should be initiated immediately upon suspicion or confirmation of MSCC to reduce cord edema and preserve neurological function while definitive therapy is arranged.
Question 3: A patient receiving cisplatin-based chemotherapy develops sudden hemoptysis, chest pain, and dyspnea. CT shows a filling defect in the pulmonary artery. Which risk factor most predisposed this patient?
- Thrombocytopenia from chemotherapy
- Cisplatin-induced hypercoagulable state (Correct answer)
- Tumor lysis syndrome
- Radiation-induced pericarditis
Correct answer: Cisplatin-induced hypercoagulable state
Cisplatin is associated with endothelial damage and a hypercoagulable state, significantly increasing the risk of venous thromboembolism including pulmonary embolism.
Question 4: A cancer patient presents with fever, confusion, and diffuse petechiae. Labs show thrombocytopenia, elevated D-dimer, prolonged PT/PTT, and low fibrinogen. Which emergent condition requires immediate treatment?
- Immune thrombocytopenic purpura (ITP)
- Heparin-induced thrombocytopenia (HIT)
- Disseminated intravascular coagulation (DIC) (Correct answer)
- Thrombotic thrombocytopenic purpura (TTP)
Correct answer: Disseminated intravascular coagulation (DIC)
DIC is characterized by simultaneous thrombosis and hemorrhage with consumption of clotting factors (low fibrinogen, elevated D-dimer, prolonged PT/PTT) and is a life-threatening emergency requiring urgent treatment.
Question 5: Which electrolyte abnormality is NOT typically associated with tumor lysis syndrome (TLS)?
- Hyperkalemia
- Hyperphosphatemia
- Hypocalcemia
- Hypernatremia (Correct answer)
Correct answer: Hypernatremia
TLS is characterized by hyperkalemia, hyperphosphatemia, hypocalcemia, and hyperuricemia resulting from massive cell lysis; sodium levels are not directly affected by intracellular contents.
Question 6: A patient with metastatic breast cancer develops altered mental status, polyuria, and constipation. Calcium is 14.2 mg/dL. Which mechanism is MOST responsible for hypercalcemia in solid tumors without bone metastases?
- Osteoclast activation by bone metastases
- PTHrP (parathyroid hormone-related protein) secretion (Correct answer)
- Excess 1,25-dihydroxyvitamin D production
- Primary hyperparathyroidism
Correct answer: PTHrP (parathyroid hormone-related protein) secretion
Humoral hypercalcemia of malignancy (HHM) is most commonly caused by tumor secretion of PTHrP, which mimics PTH and increases bone resorption and renal calcium reabsorption.
Question 7: In a patient with febrile neutropenia and an absolute neutrophil count (ANC) of 400 cells/µL, which scenario mandates inpatient hospitalization and IV antibiotics rather than outpatient oral therapy?
- Patient has controlled diabetes and lives 20 minutes from the hospital
- Patient has a MASCC score of 22
- Patient has active pneumonia and hypotension (Correct answer)
- Patient reports mild nausea but is able to swallow pills
Correct answer: Patient has active pneumonia and hypotension
Active pneumonia with hemodynamic instability (hypotension) indicates high-risk febrile neutropenia requiring immediate inpatient IV antibiotics; a MASCC score ≥21 supports low-risk outpatient management.
AOCNP Oncologic Emergencies 4
A patient with small cell lung cancer presents with hyponatremia (Na 118 mEq/L), concentrated urine, and euvolemia.
Which oncologic emergency is most likely?