Oncologic Emergencies Flashcards

A patient with small cell lung cancer presents with hyponatremia (Na 118 mEq/L), concentrated urine, and euvolemia. Which oncologic emergency is most likely?

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.

Which of the following is the FIRST-LINE treatment for malignant spinal cord compression (MSCC) once the diagnosis is confirmed?

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.

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?

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.

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?

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.

Which electrolyte abnormality is NOT typically associated with tumor lysis syndrome (TLS)?

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.

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?

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.

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?

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.