Hem n Onc 8-9 (14) Flashcards
The intramuscular influenza vaccine is the one vaccine among the answer choices that only induces ?
humoral immunity. It is an inactivated vaccine and does not produce cell-mediated immunity. Inactivated vaccines can induce B-lymphocyte immunity without T-lymphocyte involvement. A mnemonic you can use to remember inactivated vaccines is R.I.P. Always: Rabies, Influenza (injection), Polio (Salk), hepatitis A.
In contrast, live attenuated vaccines (MMR, oral polio, smallpox, yellow fever) induce both humoral and cell-mediated immunity because they are capable of replicating within the recipient. Attenuated virus produced within the vaccinated individual will be processed by ?
cells and presented on major histocompatibility complex I molecules, where they can produce a T-lymphocyte response. It is important to note that the intramuscular influenza vaccine is an inactivated vaccine, whereas the intranasal influenza vaccine is a live-attenuated virus vaccine.
The measles, mumps and rubella vaccine contains three attenuated live viruses and therefore will induce both cell-mediated and humoral immunity.
The oral polio vaccine is a live attenuated vaccine and therefore induces?
both cell-mediated and humoral immunity.
Smallpox vaccine is a live attenuated vaccine and induces both cell-mediated and humoral immunity.
The yellow fever vaccine is a live attenuated vaccine and induces both cell-mediated and humoral immunity.
This patient is presenting with hypotension, tachycardia, fever, nausea, chest tightness, and flank pain after a blood transfusion. His vital signs were stable prior to the transfusion. These signs and symptoms point to the patient having a transfusion reaction. ABO-incompatible blood leads to complement-mediated cytotoxic hypersensitivity reaction (illustrated in the diagram), a classic?
type II hypersensitivity reaction, with IgM antibodies causing complement lysis of RBCs. The reaction this patient is having to his blood transfusion is a result of IgM antibodies to an antigen on the transfused RBCs that the patient does not have on his own RBCs (eg, the patient has type A blood and receives type B blood). This results in complement activation and intravascular RBC lysis by the destructive action of complement on their membranes. As a result, symptoms such as fever and hypotension can develop. Signs of hypotension in this patient are dyspnea and tachycardia. Massive hemolysis can lead to hyperkalemia, which causes the peaked T-waves shown on the ECG in the vignette. Clerical errors are the leading cause of blood transfusion reactions.
The other answer choices do not explain this patient’s symptoms accurately:
Toxic shock syndrome is a superantigen-mediated reaction. Symptoms of toxic shock syndrome would include an initial presentation of unstable vital signs such as fever, hypotension, tachycardia, and other signs of shock, as well as a source of infection.
Type I hypersensitivity reaction is an antibody-mediated reaction via IgE and is also known as immediate hypersensitivity reaction. These reactions occur within minutes of exposure to the antigen. Anaphylactic reactions during blood transfusions have been associated with anti-immunoglobulin A (IgA) in recipients who are IgA deficient.
Type III hypersensitivity reaction is also known as an ?
immune complex reaction and occurs when complexes of antigen and IgM or IgG antibody accumulate in the circulation or in tissue, activating the complement cascade.
Type IV hypersensitivity reactions are delayed-type reactions mediated by T, CD4, and CD8 T-lymphocytes. This type of reaction occurs days or weeks after challenge with an antigen. This reaction occurs in patients who have TB skin tests, transplant rejections, or contact dermatitis.
This patient presents with fever, fatigue, unexplained weight loss, and arthralgia. Her clinical history of multiple miscarriages, combined with a positive RPR test result, point to an autoimmune disorder such as systemic lupus erythematosus (SLE). Arthritis or arthralgia associated with SLE can be asymmetric, with pain that is disproportionate to swelling, as seen in this patient. Typically, SLE affects the small joints of the hands, wrists, and knees, as opposed to rheumatoid arthritis, which is typically symmetric and polyarticular.
However, this patient’s history of multiple miscarriages (which could possibly result from deep venous thrombosis) in the past suggests ?
she has antiphospholipid antibody syndrome (APS) as well. APS can occur either as a primary disorder or secondary to autoimmune diseases such as SLE. Patients with APS are predisposed to arterial and venous thromboses, as well as recurrent fetal loss during pregnancy. The latter is believed to be due to placental insufficiency. An unexplained thrombotic event in a patient with SLE should raise suspicion for APS. The diagnosis of SLE-induced APS is made by the presence of a lupus anticoagulant, which produces a prolonged partial thromboplastin time (PTT). PTT is prolonged because the lupus anticoagulant is an antiphospholipid antibody, so it binds to the phospholipid reagent used in the PTT test. Neither test result will be altered when mixed 1:1 with fresh-frozen plasma. Although the lupus anticoagulant prolongs PTT in vitro, it predisposes to clot formation in vivo. The confirmation of lupus anticoagulant requires additional special coagulation tests.
A prolonged partial thromboplastin time (PTT) that is corrected by fresh-frozen plasma would not be expected in APS, but rather in patients with a factor deficiency (eg, hemophilia A or B).
In most circumstances, a decrease in the PT and/or aPTT reflects?
poor sample collection or preparation techniques. However, malignancy, DIC, or short-term exercise can cause decreased PT and/or aPTT.
This patient is diagnosed with follicular B-cell lymphoma and a genetic analysis shows a t(14;18) translocation. The hallmark of follicular lymphoma is t(14;18), which affects the IgH locus on chromosome 14 and the BCL-2 locus on chromosome 18, leading to overexpression of BCL-2. BCL-2 prevents apoptosis by a complex pathway that involves interaction at the mitochondrial membrane. When this gene is overexpressed, unchecked cellular proliferation ensues.
E-cadherin is a tumor suppressor protein that is normally involved in cellular adhesion, and mutations are implicated in ?
breast and stomach cancers. The IgH locus, not the BCL-2 locus, on chromosome 14 is involved in immune regulation. APC and NF1 are tumor suppressor genes that are normally involved in inhibition of signal transduction, whereas the RAS gene is involved in positive regulation of this process.
Follicular lymphoma, associated with t(14;18), affects the IgH locus on chromosome 14, and the BCL-2 locus on chromosome 18. BCL-2 regulates and ?
prevents apoptosis.
A patient who presents with abdominal fullness, fatigue, and weight loss along with splenomegaly should raise the suspicion of a hematologic malignancy. The CBC shows a reduction of hemoglobin, hematocrit, WBCs, and platelets, which is defined as pancytopenia. This is an interesting finding, since most hematologic malignancies cause an increase in WBC. In a man with splenomegaly and no lymphadenopathy, the most likely diagnosis is hairy cell leukemia.
Hairy cell leukemia is a chronic lymphoproliferative disorder characterized by ?
a proliferation of malignant B lymphocytes that have an unusual “hairy” or “ruffled” appearance due to their many long (“hairy”) cytoplasmic projections (see image; hairy cell on top, normal lymphocyte on bottom).
Hairy cell leukemia is four times more common in men than in women, and patients usually complain of abdominal fullness, fatigue, and weight loss but rarely of night sweats or fevers.The spleen is enlarged, often massively so, and lymphadenopathy is absent. This is an unusual combination of findings; usually, hematologic malignancies that cause splenomegaly also cause lymphadenopathy.
male patient with splenomegaly, pancytopenia and a “dry tap” on bone marrow aspiration should raise the suspicion of hairy cell leukemia, a B-cell chronic lymphoproliferative disorder characterized by?
the proliferation of lymphocytes with “hairy” projections in the bone marrow. The hairy cells stimulate fibrosis in the marrow, which leads to pancytopenia and a “dry tap” on bone marrow aspiration.
As for the other answes, all are associated with en elevated WBC count. Smudge cells are damaged lymphocytes seen in chronic lymphocytic leukemia and small lymphocytic leukemia; these disorders present with mature-appearing lymphocytes and a slowly progressing lymphadenopathy. Myeloblasts with Auer rods are found in acute promyelocytic leukemia, which does not cause splenomegaly.
Chronic myelogenous leukemia (CML) may present with?
fatigue and an enlarged spleen, but features numerous granulocytes. Lymphoblasts that stain positively for TdT are found in acute lymphoblastic leukemia (ALL). Additionally, bone biopsy in CML and ALL is typically successful, compared with the dry tap in this patient.
This patient presents with abnormal vaginal bleeding and decreased appetite with a discrete mass in her uterus. The histopathologic image demonstrates a leiomyosarcoma. As depicted in the image in the question, typical histologic features of leiomyosarcoma include?
spindle-shaped smooth muscle cells with varying degrees of atypia. Leiomyosarcomas also typically have an increased mitotic rate and areas of necrosis.
Sarcomas are malignant neoplasms of mesenchymal origin. Types include osteosarcoma (bone), rhabdomyosarcoma (skeletal muscle), leiomyosarcoma (smooth muscle), and liposarcoma (fat). Uterine leiomyosarcoma is a rare cause of uterine masses, accounting for only 7%-9% of all cases.
Uterine leiomyosarcomas are more common in postmenopausal women and older women. The only presenting symptom is often abnormal vaginal bleeding. A uterine mass may also be felt on pelvic exam.
Diagnosis of a uterine leiomyosarcoma preoperatively is difficult, because endometrial sampling and/or biopsy are technically difficult. Preoperative diagnosis is likely to be inconclusive due to difficulty obtaining enough tumor tissue. Therefore, the only ”gold standard” diagnosis is postoperative pathologic evaluation after hysterectomy.
Adenocarcinoma is a type of malignant tumor of epithelial mucus-producing cells, and would present?
histologically with abundant glandular structures. Papilloma is a benign neoplasm arising from surface epithelium to form finger-like fronds. Because a teratoma involves three germ cell layers, histology would demonstrate multiple types of tissue rather than abundant cells of one type. Urothelial carcinoma typically involves the bladder, ureter, urachus, and urethra, and would not present with vaginal bleeding from a discrete uterine mass.
This patient presents with recent onset seizures, headache, memory loss, and weakness in both upper extremities. A CT of the head shows irregular ring-enhancing lesions. The patient’s symptoms, age, CT scan, and biopsy results indicate a diagnosis of ?
glioblastoma multiforme (GBM). GBM is the most common primary intracranial neoplasm and is typically seen in older patients. GBMs are typically hemispheric lesions that present with a range of symptoms that include: headaches, seizures, and less commonly, memory loss, motor weakness, visual symptoms, language deficit, and cognitive and personality change.
On CT scan, GBM may exhibit classic infiltration across the corpus callosum (like that shown in this image), producing a “butterfly glioma” bilaterally. The biopsy image demonstrates a central area of necrosis surrounded by a hypercellular zone leading to the characteristic feature termed “pseudopalisading necrosis.”
