Oncology
Oncologic emergencies
Febrile neutropenia (absolute neutrophil count under 500 with fever) requires cultures and empiric antipseudomonal antibiotics within 60 minutes. Suspected spinal cord compression demands dexamethasone and urgent MRI of the entire spine before neurologic deficits become fixed. Tumor lysis syndrome produces hyperkalemia, hyperphosphatemia, hypocalcemia, and hyperuricemia - treat with aggressive fluids and rasburicase or allopurinol. Hypercalcemia of malignancy is managed with isotonic fluids followed by a bisphosphonate or denosumab. Superior vena cava syndrome causes facial plethora and distended neck veins from lung cancer or lymphoma.
Paraneoplastic syndromes
Know the classic associations: SIADH and Cushing syndrome with small cell lung cancer, hypercalcemia with squamous cell carcinoma and myeloma, and polycythemia with renal cell carcinoma. Back pain in a patient with known cancer is metastasis until proven otherwise.
Treatment toxicity and supportive care
Anthracyclines are cardiotoxic (monitor ejection fraction), bleomycin causes pulmonary fibrosis, cisplatin causes nephrotoxicity and neuropathy, vincristine causes neuropathy, and methotrexate causes mucositis with rescue by leucovorin. Immune checkpoint inhibitors cause colitis, thyroiditis, hepatitis, and pneumonitis - treat significant toxicity with corticosteroids and hold the drug. Address pain, nutrition, and goals of care early.
Worked example
A patient with breast cancer and new thoracic back pain plus leg weakness needs dexamethasone now and an urgent MRI of the whole spine - do not wait for plain films.