LE6 REVIEW ONCO Flashcards

Question

7. Which chemotherapy agent is associated with pseudotumor cerebri (idiopathic intracranial hypertension)? A. Methotrexate B. Tretinoin (ATRA) C. Cyclophosphamide D. Rituximab

Answer 1

B. Tretinoin (ATRA) Rationale: Tretinoin (used for acute promyelocytic leukemia) can cause increased ICP, leading to pseudotumor cerebri.

Answer 2

B. Leptomeningeal enhancement Rationale: Leptomeningeal enhancement on MRI is a key finding in neoplastic meningitis.

Answer 3

B. Intrathecal Rationale: Intrathecal chemotherapy (methotrexate, cytarabine) is the mainstay of treatment for neoplastic meningitis.

Answer 4

B. Metastatic CNS disease Rationale: Metastatic brain lesions are the most common cause of seizures in cancer patients.

Answer 5

D. Temporal Rationale: Temporal lobe involvement is most commonly associated with seizures in brain tumors.

Answer 6

B. Posterior reversible leukoencephalopathy syndrome (RPLS) Rationale: RPLS is associated with chemotherapy and targeted therapy, presenting with seizures, headache, and visual disturbances.

Answer 7

C. Acute Myeloid Leukemia (AML) Rationale: AML is the most common cause of leukostasis syndrome, occurring in 5–13% of AML cases, while ALL accounts for 10–30% of cases. Chronic leukemias (CML, CLL) rarely cause leukostasis.

Answer 8

B. Brain and lungs Rationale: The brain (intracerebral leukostasis) and lungs (pulmonary leukostasis) are the most commonly affected organs, leading to neurologic and respiratory compromise.

Answer 9

B. Papilledema and retinal hemorrhages Rationale: Intracerebral leukostasis can cause papilledema, retinal vein distension, and retinal hemorrhages, along with neurologic deficits such as ataxia, confusion, and coma.

Answer 10

A. Squamous cell carcinoma of the lung Rationale: Squamous cell carcinoma of the lung is the most common malignant cause of hemoptysis, due to its tendency to invade bronchial vessels.

Answer 11

A. Stop bevacizumab and perform bronchoscopy Rationale: Bevacizumab (anti-VEGF) increases the risk of life-threatening hemoptysis, particularly in squamous cell lung cancer. Bronchoscopy helps localize the bleeding site.

Answer 12

B. Bronchial artery embolization Rationale: The first-line definitive treatment for massive hemoptysis (≥ 100–600 mL of blood expectorated in 24 hours) is bronchial artery embolization (BAE). It is a minimally invasive procedure that effectively stops bleeding by occluding abnormal bronchial arteries supplying the affected lung area.

Answer 13

B. Hoarseness Rationale: Hoarseness suggests laryngeal involvement, commonly seen in lung, esophageal, and thyroid cancers.

Answer 14

B. Acute lymphoblastic leukemia (ALL) Rationale: TLS occurs most frequently in rapidly proliferating tumors like ALL, AML, Burkitt lymphoma, and high-grade non-Hodgkin lymphoma.

Answer 15

B. Hyperuricemia Rationale: The earliest electrolyte abnormality in tumor lysis syndrome (TLS) is hyperuricemia, which occurs due to the rapid breakdown of tumor cells, leading to the release of nucleic acids that are metabolized into uric acid. • Hyperuricemia (B) develops first because nucleic acid breakdown happens rapidly after chemotherapy or spontaneous tumor lysis. Uric acid is poorly soluble in acidic urine, increasing the risk of acute kidney injury. • Hyperphosphatemia (A) follows as intracellular phosphate is released from lysed cells. • Hyperkalemia (C) occurs due to massive cell lysis, leading to potassium release into the bloodstream. • Hypocalcemia (D) is secondary to hyperphosphatemia, as phosphate binds to calcium, reducing its serum levels.

Answer 16

B. Cytokine release syndrome Rationale: Infusion reactions are caused by cytokine release (IL-6, TNF-α, IL-10) from activated immune cells, leading to fever, hypotension, and respiratory symptoms.

Answer 17

B. Schistocytes Rationale: Schistocytes (fragmented RBCs) are characteristic of microangiopathic hemolytic anemia (MAHA) seen in HUS.

Answer 18

B. Hemolytic anemia, thrombocytopenia, renal failure Rationale: Hemolytic-uremic syndrome (HUS) is classically defined by the triad of: 1. Microangiopathic hemolytic anemia (MAHA) – characterized by schistocytes on peripheral smear, elevated LDH, and low haptoglobin. 2. Thrombocytopenia – due to platelet consumption in microthrombi formation. 3. Acute renal failure – caused by endothelial damage in renal microvasculature.

Answer 19

A. Plasma exchange Rationale: Plasma exchange (plasmapheresis) is the first-line treatment for HUS associated with factor H antibodies.

Answer 20

A. Methotrexate Rationale: Methotrexate is a well-known cause of pulmonary toxicity, along with Bleomycin, Busulfan, Gemcitabine, and Ifosfamide.

Answer 21

C. Leukemic infiltration of the lungs Rationale: Leukemic infiltration is common in hematologic malignancies, often presenting as diffuse interstitial infiltrates or bronchovascular thickening.

Answer 22

B. Pulmonary lymphangitic carcinomatosis Rationale: Pulmonary lymphangitic carcinomatosis is caused by tumor cell invasion of lymphatic vessels, most often seen in breast, lung, and stomach cancers.

Answer 23

B. Ground-glass opacities Rationale: Radiation pneumonitis presents with ground-glass opacities and fibrosis, typically in the radiation field.

Answer 24

B. Acute myeloid leukemia (AML) Rationale: Neutropenic enterocolitis occurs most frequently in AML and ALL patients receiving high-dose cytotoxic chemotherapy.

Answer 25

A. Cecal wall thickening >10 mm Rationale: Cecal wall thickening (>10 mm) with mesenteric stranding on CT is a hallmark of neutropenic enterocolitis.

Answer 26

A. Clostridium difficile Rationale: C. difficile, Enterobacteriaceae, and Pseudomonas species are common pathogens in neutropenic enterocolitis.

Answer 27

B. Ifosfamide Rationale: Cyclophosphamide and Ifosfamide are the two chemotherapy agents most commonly associated with hemorrhagic cystitis due to their toxic metabolite, acrolein.

Answer 28

B. Mesna Rationale: Mesna binds acrolein, detoxifying it and preventing bladder toxicity. It is routinely given with ifosfamide and high-dose cyclophosphamide.

Answer 29

B. Gross hematuria Rationale: Gross hematuria is the classic feature of hemorrhagic cystitis, often accompanied by urinary urgency, frequency, and dysuria.

Answer 30

B. Doxorubicin Rationale: Anthracyclines like doxorubicin cause irreversible congestive heart failure (CHF) due to dose-dependent myocardial damage and myofibrillar dropout.

Answer 31

B. Trastuzumab Rationale: Trastuzumab-induced cardiotoxicity is NOT dose-dependent and is usually reversible upon discontinuation.

Answer 32

B. Congestive heart failure Rationale: Anthracycline-induced cardiomyopathy is a leading cause of non-cancer-related mortality in childhood cancer survivors.

Answer 33

B. Bleomycin Rationale: Bleomycin causes dose-dependent pneumonitis and pulmonary fibrosis. Cumulative doses >400 units increase the risk.

Answer 34

C. Fine "Velcro" crackles Rationale: Pulmonary fibrosis causes fine inspiratory crackles ("Velcro rales") due to alveolar fibrosis and restriction of lung expansion.

Answer 35

B. Pulmonary function test (DLco) Rationale: DLco (Diffusion capacity of carbon monoxide) is the most sensitive test for detecting early chemotherapy-induced pulmonary damage.

Answer 36

B. Alkylating agents Rationale: Alkylating agents like cyclophosphamide, melphalan, and ifosfamide cause DNA damage, increasing the risk of secondary acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS).

Answer 37

B. Radiation therapy Rationale: Radiotherapy increases the risk of secondary malignancies, including breast, lung, thyroid, and sarcomas, particularly when exposure occurs at a young age.

Answer 38

B. A second primary breast cancer Rationale: Breast cancer survivors treated with radiation have an increased risk of developing a second primary breast cancer in the opposite breast.

Answer 39

B. Methotrexate Rationale: Methotrexate is the most common chemotherapeutic agent associated with acute and delayed encephalopathy, particularly when administered intrathecally.

Answer 40

C. Cisplatin Rationale: Cisplatin causes sensorineural hearing loss by damaging cochlear hair cells, particularly at high doses.

Answer 41

A. Vincristine Rationale: Vinca alkaloids like vincristine cause peripheral neuropathy in a characteristic stocking-glove distribution.

Answer 42

B. Lhermitte’s sign Rationale: Lhermitte’s sign is an electric shock-like sensation down the spine upon neck flexion, often seen in patients with radiation myelopathy or high-dose methotrexate therapy.

Answer 43

B. Peripheral neuropathy Rationale: Cisplatin and other platinum-based agents commonly cause sensory neuropathy, presenting as paresthesias, loss of vibratory sensation, and proprioception.

Answer 44

B. Rasburicase Rationale: Rasburicase enzymatically degrades uric acid and is superior to allopurinol in high-risk TLS patients.

Answer 45

A. Tocilizumab Rationale: Tocilizumab (IL-6 inhibitor) is the preferred treatment for severe cytokine release syndrome (CRS).

Answer 46

B. Gemcitabine Rationale: Gemcitabine, Mitomycin, and VEGF inhibitors are the most common chemotherapy-related causes of HUS.

Answer 47

A. Rituximab Rationale: Rituximab can cause cytokine release syndrome due to rapid activation of B cells and macrophages, leading to fever, hypotension, and hypoxia.