heme/onc 5 Flashcards
What are associated with the highest risk?
Burdens
What is oxidized from ferrous (Fe2+) to ferric state (Fe3+)?
Hemoglobin
What becomes methemoglobin?
Hemoglobin when all four heme molecules are ferric instead of ferrous.
What cannot bind oxygen?
Hemoglobin when all four heme molecules are ferric instead of ferrous.
What usually happens to one or two of the iron atoms under the influence of oxidizing drugs?
They become ferric.
What happens to the affinity of the remaining ferrous-bearing heme molecules for oxygen?
It increases, shifting the hemoglobin–oxygen dissociation curve left.
What is the effect of the left shift in the hemoglobin–oxygen dissociation curve?
Diminishing oxygen delivery to the tissues.
What is the most likely diagnosis in a person with HIV showing thrombocytopenia?
Immune thrombocytopenia.
What shows thrombocytopenia with a few large platelets?
Peripheral-blood smear.
What are most palpable testicular tumors in adults?
Malignant.
What should a patient with thymoma have for further diagnostics?
A chest radiograph.
What condition is typically idiopathic but can occur in patients with hematologic malignancies?
Pure red cell aplasia.
What viral illnesses can lead to pure red cell aplasia?
Parvovirus, HIV, or hepatitis C.
What medications can cause pure red cell aplasia?
Phenytoin or trimethoprim–sulfamethoxazole.
What is a febrile transfusion reaction?
A reaction that can occur during blood transfusion.
What is a transfusion reaction?
A transfusion reaction is defined as fever >38°C or an increase of at least 1°C from baseline that occurs during or up to 4 hours after a blood transfusion.
What is a lupus anticoagulant?
A lupus anticoagulant is an antibody that leads to a prolonged prothrombin time or partial-thromboplastin time, causing an increase in clotting, not bleeding.
What test is most appropriate for a patient who becomes febrile after receiving a correctly matched unit of packed red cells?
A postreaction direct antiglobulin test to rule out a hemolytic transfusion reaction.
What is the risk associated with men who have a history of cryptorchidism?
Men with a history of cryptorchidism have an increased risk for the development of cancer in either testicle.
What condition is indicated by hemolytic anemia and a positive Coombs test for anti-C3 and negative for anti-immunoglobulin G?
This condition is cold agglutinin hemolytic anemia.
What must be ruled out by measurement of ristocetin cofactor activity in essential thrombocythemia?
Acquired von Willebrand syndrome must first be ruled out.
When can screening mammography be discontinued?
Screening mammography can also be discontinued in women with a life expectancy of less than 5 to 10 years.
What hematologic effect is associated with treatment using methotrexate?
Macrocytosis is a hematologic effect of treatment with methotrexate.
What is tumor lysis syndrome (TLS)?
Tumor lysis syndrome is caused by the release of the contents of malignant cells into the bloodstream, resulting in electrolyte abnormalities.
What electrolyte abnormalities may occur in tumor lysis syndrome?
Electrolyte abnormalities may include hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia.
What should be evaluated for the diagnosis of multiple myeloma?
Evaluate for proteinuria, anemia, and kidney disease.
What is the significance of G6PD deficiency?
G6PD deficiency leads to the destruction of erythrocytes.
What causes the denaturation of globin chains in deficient erythrocytes?
High levels of oxidants cause a cross-linking of sulfhydryl groups on globin chains, leading to their denaturation and the formation of Heinz bodies.
What INR level is associated with an increased risk for bleeding?
An INR greater than 4.0 has been associated with an increased risk for bleeding.
How does the risk for intracranial hemorrhage change with INR levels?
The risk for intracranial hemorrhage increases approximately twofold for every one-unit increase in INR.
When can pharmacologic thromboprophylaxis generally be started after major orthopedic surgery?
Pharmacologic thromboprophylaxis can generally be started 8 to 12 hours after surgery.
What percentage of bladder cancers are urothelial carcinomas?
Ninety percent of bladder cancers are urothelial carcinomas.
What percentage of bladder cancers are squamous-cell carcinomas?
Ten percent of bladder cancers are squamous-cell carcinomas.
Where do osteosarcomas generally arise?
Osteosarcomas generally arise in the metaphysis of the bone.
What is the recommended screening for people aged 50 to 80 years with a history of smoking?
Current guidelines recommend annual screening with low-dose chest CT for people age 50 to 80 years who have a history of at least 20 pack-years of cigarette smoking.
Can Rh-negative blood be given to Rh-positive patients?
Yes, one can give Rh-negative blood to Rh-positive patients but not the other way around.
Is complement depletion seen in both PAN and GPA?
Complement depletion is typically not seen in either PAN or GPA.
What is characteristically seen in certain ethnicities regarding neutrophil counts?
Asymptomatic isolated absolute neutrophil counts below the laboratory reference range are characteristically seen in patients of certain ethnicities, including people of African descent who typically do not express the Duffy allele.
What should be considered as a likely diagnosis in a patient with urticaria pigmentosa and anaphylaxis?
Systemic mastocytosis should be considered as a likely diagnosis in such patients.
When should positron emission tomography and electron microscopy be used?
They should be used only if the diagnosis is unclear after light microscopy and IHC analysis.
What is the haptoglobin level in autoimmune and microangiopathic hemolytic anemias?
The haptoglobin level is low in both autoimmune and microangiopathic hemolytic anemias.
Is the haptoglobin level low in both autoimmune and microangiopathic hemolytic anemias?
True
What do the National Comprehensive Cancer Network guidelines recommend monitoring after neck irradiation?
Thyroid-stimulating hormone levels every 6 to 12 months.
What is the most likely diagnosis in a patient with pancytopenia without myeloid immaturity or leukoerythroblastosis?
Gaucher disease
Massive hepatosplenomegaly without lymphadenopathy and bone pain.
What are the characteristic imaging findings of HCC in chronic liver disease with elevated serum alpha-fetoprotein?
Sufficiently specific and obviate the need for tissue diagnosis.
What can be typically used to treat excessive bleeding with likely factor 8 inhibition?
Prothrombin complex concentrate or recombinant human factor VIIa.
What is the diagnosis for a patient presenting after an atypical lung infection with hemolytic anemia?
Cold agglutinin hemolytic anemia
Positive Coombs test for anti-C3 and negative for anti-immunoglobulin G.
What findings are consistent with a diagnosis of low-grade lymphoma in a patient with hepatitis C virus infection?
Splenomegaly and diffuse lymphadenopathy.
What are the most common intracranial tumors in adults?
Brain metastases.
What type of tumors are most common in cryptorchid testicles?
Pure seminomas.
What happens in a mixing study if the prolonged aPTT is caused by a lack of clotting factors?
The factors contained in the normal plasma will normalize the aPTT.
What is the treatment of choice for an advanced inoperable or metastatic gastrointestinal stromal tumor?
A tyrosine kinase inhibitor such as imatinib.
What are the most common malignant tumors in males aged 15 to 35?
Testicular tumors.
What condition is characterized by myeloid immaturity or leukoerythroblastosis?
Gaucher disease
What is associated with massive hepatosplenomegaly without lymphadenopathy?
Gaucher disease
What symptom is commonly present in Gaucher disease?
Bone pain
What leukocyte count indicates the highest risk category for TLS?
> 50,000 cells per mm3
What is the risk of cervical cancer in people with HIV?
Much higher than in the general population
What is the blast count in patients with accelerated-phase CML?
10% to 20%
What is the blast percentage in patients with CML in blast crisis?
> 20% blasts in peripheral blood or bone marrow
What condition is classically associated with microangiopathy?
Thrombotic thrombocytopenic purpura
What are common symptoms of thrombotic thrombocytopenic purpura?
Thrombocytopenia, renal insufficiency, mental status changes, and fever
What is the most appropriate approach to managing intractable back pain in a patient with metastatic cancer?
Initiate bolus doses of intravenous opioids
What should be monitored in patients receiving bevacizumab?
Urine protein
What is the first-line treatment for severe cases of methemoglobinemia?
Administration of intravenous methylene blue
What does methylene blue activate in the body?
The NADPH-dependent methemoglobin reductase system
What is the role of the methemoglobin reductase system?
It rapidly reduces methemoglobin back to hemoglobin.
What treatment may ITP patients who relapse or are unresponsive to dexamethasone respond to?
They may respond to intravenous immunoglobulin stimulation of platelet production with eltrombopag or romiplostim.
What is splenectomy reserved for?
It is reserved for patients refractory to medical management.
What causes Porphyria cutanea tarda (PCT)?
PCT is caused by an acquired deficiency of hepatic uroporphyrinogen decarboxylase.
What is the most likely diagnosis in a patient with recurrent epistaxis, telangiectasia, and anemia?
Hereditary hemorrhagic telangiectasia.
What characterizes TTP?
TTP is characterized by deficiency of ADAMTS13, a plasma protease that normally cleaves ultra-large von Willebrand-factor multimers.
What should a patient with likely lymphoma presenting with progressive cervical adenopathy undergo?
They should be urgently evaluated with a chest radiograph.
What imaging is needed for a patient with suspected malignant airway obstruction?
A chest radiograph is the best and safest immediate choice.
What is acute promyelocytic leukemia sensitive to?
It is very sensitive to the vitamin A derivative all-trans retinoic acid and to arsenic.
What are RCTs best designed to find out?
RCTs are best designed to find out whether a treatment has caused a specific measured effect in a select population.
What are the most common primary tumors that metastasize to the brain?
The most common primary tumors that metastasize to the brain are lung cancer.
