Hem n Onc 8-6 (5) Flashcards Preview

Hematology and Oncology USMLE 1 > Hem n Onc 8-6 (5) > Flashcards

Flashcards in Hem n Onc 8-6 (5) Deck (29):

The most common causes of cancer death in men by percentage of total deaths due to cancer are:
Lung (102 per 100,000)
Prostate (70 per 100,000)
Colorectal (44 per 100,000)
Liver cancer is ?

the fourth most common cause of cancer death in men (9.5 per 100,000), and among Asian and Pacific Islander men is it the second most common cause of cancer death. Testicular cancer is a relatively rare cause of cancer death in men, accounting for only about 0.6% of male cancer deaths.

In men, the most common causes of cancer (not cancer death) by estimated new cases per year are: prostate cancer, followed by lung and then colorectal cancer.


This patient presents after 3 weeks of fever and weight loss and exhibits pallor, hepatomegaly, and splenomegaly. These symptoms, along with her laboratory test results, are consistent with hemophagocytic lymphohistiocytosis (HLH), which is confirmed by the bone marrow aspiration, demonstrating hemophagocytes. Hemophagocytes (red arrow in image) are macrophages that have engulfed red blood cells (RBCs) and lymphocytes. Familial-type HLH is an autosomal recessive defect in several genes, including perforin-related genes, whereas the secondary type is frequently due to?

infection with Epstein-Barr virus. HLH involves the abnormal activation and proliferation of lymphohistiocytes, leading to hemophagocytosis and the upregulation of proinflammatory cytokines. The immune system becomes overstimulated and can begin attacking native cells in the bone marrow (as seen in the image in the vignette), the liver, and brain. Treatment consists of a combination of etoposide, corticosteroids, and methotrexate, although stem cell transplantation is often required.


Ewing sarcoma usually presents in the second decade of life with fever, weight loss, bone tenderness, and pathologic fractures. This patient is only 2 years old, and bone marrow aspiration from a patient with Ewing sarcoma would not demonstrate the findings shown in the image.
Multiple myeloma presents in the elderly with renal injury, pathologic fractures, and hypercalcemia. A bone marrow aspirate would show red blood cells (RBCs) in rouleaux formation, stacks of RBCs pushed together by excessive protein, in contrast to this patient’s findings.
Neuroblastoma manifests with constitutional symptoms (fever, weight loss, pallor, hepatosplenomegaly), hypertension, abdominal pain, and an abdominal mass. These symptoms are not consistent with this patient’s presentation.
Wilms tumor manifests as an?

asymptomatic flank mass and/or gross hematuria.
Autoimmune lymphoproliferative syndrome is a rare inherited disorder of apoptosis, which is most commonly due to mutations in the FAS gene. Like HLH, it presents with chronic lymphadenopathy, splenomegaly, and symptomatic cytopenias in an otherwise healthy child. Although specific tests are required to rule out this diagnosis, the ferritin level is typically less than 3000 μg/L, as opposed to the highly elevated ferritin level seen in this patient.


This patient has severe swelling, pain, and redness of the hands and fee; and he has SCD. Dactylitis is a known complication of SCD and occurs because the deformed RBCs block blood circulation. SCD is the result of a?

single nucleotide substitution causing a change from a glutamate (GAG) to a valine (GTG) amino acid on position 6 of the ß-globin gene within DNA.


Codons are three-nucleotide RNA molecules on messenger RNA (mRNA) that code for a particular amino acid. Anticodons are three-nucleotide RNA molecules on transfer RNA (tRNA) that help identify and transfer amino acids to be used in protein translation. Codons and anticodons adhere to the same nucleotide rules that are true for DNA and RNA in general. Adenine pairs with thymine (in DNA) or uracil (in RNA), whereas cytosine pairs with guanine. The codon on the mRNA strand and the anticodon on the tRNA strand are lined up in an antiparallel manner. In this case, we are told that the DNA mutation is 5'-GTG. If we were to translate this to an mRNA codon, it would be?

5'-GUG. Subsequently, the tRNA anticodon for this section of the mRNA would be 5'-CAC.


5'-AGG is incorrect because it does not match up with the anticodon in an antiparallel manner.
5'-CTC and 5’-GTG are incorrect because thymine is not present in RNA.
5'-GUG represents the ?

mRNA sequence for the DNA mutation, not the tRNA anticodon.


This patient is taking heparin and develops thrombocytopenia. The most likely diagnosis is thrombocytopenia secondary to heparin administration. Heparin-induced thrombocytopenia (HIT) is an immunologic reaction to heparin, producing antibodies that cross-react with platelet factor 4, leading to?

platelet activation and clumping.


Ascending paralysis is an unlikely result of HIT as this patient’s antibodies do not cross-react with components of the nervous system.
Rhabdomyolysis, or muscle necrosis, can result from muscle injury such as traumatic compression. However, this patient’s autoantibodies do not cross-react with muscle.
Skin necrosis may result from ?

.warfarin initiation, but does not occur with HIT.
Jaundice can have many causes, including hemolytic anemia and biliary obstruction. While in theory it may occur due to thrombosis of the hepatic vessels, this is a low risk in HIT


This patient's physical exam demonstrates Courvoisier sign, jaundice and a palpable, enlarged, nontender gallbladder. Courvoisier sign can be found in patients with cancer in the head of the pancreas that is obstructing the distal common bile duct, preventing the gallbladder from emptying. Jaundice is also a sign of biliary obstruction. Patients may also present with significant weight loss and new onset of diabetes mellitus, as the exocrine function of the pancreas becomes compromised.
Approximately 95% of malignant pancreatic neoplasms come from?

exocrine cells. In older patients with sudden insulin insensitivity and a diabetes mellitus diagnosis, pancreatic cancer should be considered. Smoking is the most important environmental risk factor for the development of pancreatic cancer. Treatment usually involves resection of the pancreatic head, duodenum, distal stomach, and gallbladder (Whipple procedure).


Acute hepatitis is unlikely, given the patient’s normal liver function tests. With a palpable mass, cancer is more likely than choledocholithiasis, a stone in the common bile duct. Cholelithiasis refers to stones in the gallbladder, and may present with abdominal pain, nausea, and vomiting, Hemolytic anemia is associated with?

jaundice characterized by a predominantly indirect hyperbilirubinemia, but not an enlarged, palpable mass.


This child presents with signs and symptoms (fever, lethargy, and decreased appetite) that would typically prompt an investigation for infection, starting with a CBC. The white blood cell count in this child is elevated to a degree never seen in an infectious process, so examination of the blood smear is critical.
The blood smear shows a sea of uniform blasts, which is diagnostic of acute leukemia. The blasts have no distinguishing features such as Auer rods (which would be diagnostic of acute myeloblastic leukemia), so a definitive diagnosis of the type of acute leukemia (myeloid or lymphoid) cannot be made. However, in children who present with acute leukemia, the presumptive diagnosis is ?

acute lymphoblastic leukemia . until proven otherwise.


Lymphoblastic leukemia is indicated by greater than 20% leukemic blasts. Patients with acute lymphoblastic leukemia (ALL) often present with?

neutropenia, because the rapid proliferation of WBCs crowds out production of other cells and causes bone marrow failure. They would also present with fatigue, weight loss, night sweats, lymphadenopathy, and anemia.


In acute leukemia of any type, the rapid proliferation of blasts leads to an increase (not a decrease) in serum markers of cell lysis such as lactate dehydrogenase and uric acid. Polycythemia (an increase in red cells) and thrombocytosis (an increase in platelets) are not seen in ?

acute lymphoblastic leukemia. In fact, you see the opposite—anemia and thrombocytopenia—because lymphoblasts crowd out normal hematopoietic precursors in the marrow.


This patient presents with a maculopapular rash, along with a recent history of fever, headaches, malaise, and tick exposure. His blood smear shows berry-like cytoplasmic inclusions in neutrophils, which suggests that the patient contracted?

ehrlichiosis (specifically human monocytic ehrlichiosis).Ehrlichiosis is caused by an obligate intracellular gram-negative species of rickettsiales bacteria, Ehrlichia chaffeensis. As with most rickettsial diseases, it is carried by a tick vector (in this case, the Lone Star tick), with dogs being common vectors. Ehrlichia forms characteristic berry-like cytoplasmic inclusions in macrophages or neutrophils (seen in the image).


Babesiosis is a tick-borne illness that presents with fevers, chills, myalgias, and gastrointestinal symptoms, such as anorexia, nausea, and dark urine. It is known to cause hemolytic anemia, thrombocytopenia, and increased serum creatinine and BUN.
Lyme disease is caused by Borrelia burgdorferi and produces a characteristic target lesion known as erythema chronicum migrans.
Rocky mountain spotted fever, caused by Rickettsia rickettsii, usually causes a characteristic rash that involves the soles and palms.
Typhus fever is caused by ?

members of the genus Rickettsia and is associated with transmission through the feces of fleas and lice. It is usually associated with cramped, unsanitary conditions or exposure to flea-carrying rats.


This patient presents with dermatitis (as seen in the vignette image), hepatitis (elevation in liver enzymes), and gastroenteritis, a classic triad of symptoms suggesting that the patient is undergoing acute graft-versus-host disease (GVHD). Bilirubin elevation may also be observed. Acute GVHD is a serious complication of allogeneic blood or marrow transplantation and is mediated by donor lymphocytes reacting against major or minor histocompatibility antigens on recipient cells that are recognized as foreign. It occurs ?

weeks after transplantation. Acute GVHD often manifests with erythematous macules on the face or palms and soles, whereas generalized eruptions resemble measles. Acute GVHD usually arises within 60 days of bone marrow transplantation. Chronic GVHD evolves from acute GVHD and occurs weeks to months after transplantation and may appear lichenoid and, in time, sclerodermoid in appearance.


ABO incompatibility occurs when there is transfusion of incompatible blood types.
Primary/acute graft rejection is mediated by the recipient immune system against alloantigens expressed on donor stem cells. There would be a subsequent failure of the bone marrow graft to successfully replete cell counts in the usual time frame expected after transplantation.
Hyperacute rejection is seen only in?

solid-organ transplants. It is an antibody-mediated (type II) reaction due to the presence of preformed antidonor antibodies in the transplant recipient.


This patient presents with fatigue, weight loss, and an elevated white blood cell count. Additionally, he is anemic and thrombocytopenic. These symptoms are fairly nonspecific, but the blood smear is notable for destroyed lymphocytes (smudge cells). The findings are characteristic of?

chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL). In both CLL and SLL, the body produces high numbers of abnormal B-lymphocytes. Both CLL and SLL are similar disorders, differing only in the degree of peripheral lymphocytosis, which must be >4000 cells/mm³ to qualify as CLL.


When a peripheral blood smear is created on a CLL/SLL patient, many of these fragile lymphocytes are flattened in the process, producing the smudge cells indicated by the circles in this cropped version of the vignette image shown here. These cells have a distinct immunophenotype, expressing B-lymphocyte markers including CD5, CD19, CD20, and CD23. Although CD5 is generally a marker for T-cells, it is also seen in?

primitive B-cells in these leukemias. It is thought that CLL/SLLs originate from B lymphocytes, which normally produce antibodies in the humoral immune system.


Activation of cytotoxic lymphocytes by costimulation is a function of helper T-cells, and recognition/destruction of antigens on virus-infected host cells is a function of cytotoxic T-cells. Both of these cells are a part of cell-mediated immunity, not humoral immunity. Engulfing bacteria and killing them in an oxidative respiratory burst is a ?

function of neutrophils, which are a part of the innate immune system. Transportation of oxygen is a function of red blood cells.


This patient reports having heavy menstrual periods and increased frequency of nosebleeds. She also has petechiae and a low platelet count. Based on her clinical presentation, she most likely has ?

immune thrombocytopenic purpura (ITP), an autoimmune disease characterized by a low platelet count and easy bruising or bleeding through skin or mucous membranes. On a blood smear (shown in this image), platelets may be abnormally large because of increased platelet production. There also tend to be more megakaryocytes in the marrow.


RBCs with missing semicircular portions describe bite cells, which are red blood cells with missing portions caused by splenic macrophage removal of denatured and agglomerated hemoglobin, occurring in glucose-6-phosphate dehydrogenase deficiency.
Crescent-shaped RBCs are termed drepanocytes and are found in sickle cell disease.
RBCs with cytoplasmic basophilic remnants represent ?

Howell-Jolly bodies and are seen in patients with splenic dysfunction and those who have undergone splenectomy.
Pappenheimer bodies are siderosomes, or iron bodies, which appear as blue-purple granules on Wright staining of RBCs. Pappenheimer bodies are seen in sideroblastic anemia.


The patient presents with marked fever, tachycardia, tachypnea, leukocytosis, elevated D-dimer level, and pleuritic chest pain, which is highly suggestive of a pulmonary embolism (PE). In addition, the patient has signs of a deep vein thrombosis (DVT) with erythema, edema, and tenderness to deep palpation in her right leg. The etiology of a hypercoagulable state in a young patient is unusual but can be observed in those taking oral contraceptives. However, our patient denied such a history, so a genetic predisposition for hypercoagulability must be considered.
Factor V Leiden is the most common inherited cause of ?

hypercoagulability, a pathologic state that predisposes the affected individual to thrombus formation. Normally, activated protein C cleaves factor V, terminating the clotting cascade. In people with factor V Leiden, factor Va is resistant to this cleavage, preventing protein C from degrading factor V. A heterozygosity for factor V Leiden conveys a fivefold increased risk of DVT or PE, whereas homozygosity confers a 90-fold increased risk.


A mutation in the prothrombin G20210A gene—a genetic defect that causes the prothrombin level to increase—is the second most common cause of inherited hypercoagulability.
Genetic absence of antithrombin III is a severe but rare cause of inherited hypercoagulability.
Protein deficiencies resulting in increased factor Va and VIIIa (protein C and protein S deficiencies) confer a greater risk for?

developing DVT or PE but are less common than a mutation in the factor V Leiden or prothrombin G20210A gene.
Dysfibrinogenemia, in which genetically abnormal fibrinogen causes clots, should be considered after the other causes of hypercoagulability have been ruled out.


This patient presents with invasive ductal carcinoma of the breast, and is treated aggressively with chemotherapy. Her physician includes an agent that has the adverse effect of numbness and tingling of the hands and feet, or peripheral neuropathy. Vincristine is a chemotherapeutic agent used to treat ovarian cancer and as an adjuvant to breast cancer treatment.
Vincristine can potentially cause the?

adverse effect of peripheral neuropathy. It is an M-phase-specific agent that binds to tubulin subunits, thereby disrupting microtubule dynamics and causing mitotic arrest. Many chemotherapeutic drugs work by interrupting microtubule function, including paclitaxel, vincristine, vinblastine, griseofulvin, albendazole, mebendazole, and colchicine.


As a result of microtubule disruption, patients may experience peripheral neuropathy due to impaired neurotransmitter transport, requiring the microtubule network to transport vesicles from the cell body to the synaptic terminal. Other adverse effects include myelosuppression and myalgias.

Peripheral neuropathy is implicated with chemotherapeutic agents that impair microtubule formation. Blockage of estrogen receptors or DNA destabilizing agents are therefore unlikely to?

produce neuropathy. A monoclonal antibody against HER2 would be used for metastatic breast cancer. Methotrexate, which inhibits DNA synthesis, is not known for producing tingling of the hands and feet.


This patient presents to the ED with a presumed fracture of the right femur, as well as longstanding issues concerning bone pain, dyspnea, and fatigue. Her lab findings depict pancytopenia, proteinuria, and hypercalcemia, which strongly suggest that her fracture is pathologic, due to an underlying multiple myeloma (MM). As seen in the patient, MM can manifest with pancytopenia with anemia, thrombocytopenia, leukopenia, and decreased reticulocyte count. Bone marrow is actively suppressed due to ?

the hyperproliferation of plasma cells. A history of bone pain and pathologic fracture is also common, especially in the setting of hypercalcemia. The bone pain is caused by lytic lesions, which release calcium, causing hypercalcemia.


Multiple myeloma is a proliferation of malignant plasma cells resulting in lytic lesions, pathologic fractures, hypercalcemia, bone marrow suppression, and excessive production of λ light-chain IgG immunoglobulins. Immunoglobulin circulation causes?

Bence Jones proteinuria and blood hyperviscosity, resulting in RBC rouleaux (roll of coins) appearance.


Broken and destroyed lymphocytes on peripheral blood smear are called smudge cells, which are typically seen in the setting of chronic lymphocytic leukemia (CLL).
Chronic myelogenous leukemia (CML) is characterized by?

increased circulating promyelocytes and myelocytes, thrombocytopenia, and normocytic anemia.
Microcytosis and hypochromasia are typical of iron deficiency anemia.
Myeloblasts with Auer rods are seen in many types of acute myeloid leukemia, including AML-M1, AML-M2, AML-M3, and AML-M4.