6/12 UWorld

Question 1

What are the cartilage, muscle, and nerve derivatives of the 1st branchial arch?

Answer 1

• Cartilage:
  
  • Maxillary process, mandibular process, incus, malleus
• Muscles:
  
  • Muscles of mastication, mylohyoid, tensor tympani, tensor veli palatine
• Nerves:
  
  • CN V2 and V3

Question 2

What are the cartilage, muscle, and nerve derivatives of the 2nd branchial arch?

Answer 2

• Cartilage:
  
  • Stapes, styloid, stylohyoid
• Muscles:
  
  • Muscles of facial expression
  • Stapedius, stylohyoid
• Nerves:
  
  • CN VII

Question 3

What are the cartilage, muscle, and nerve derivatives of the 3rd branchial arch?

Answer 3

• Cartilage:
  
  • Greater horn of hyoid
• Muscles:
  
  • Stylopharyngeus
• Nerves:
  
  • CN IX

Question 4

What are the cartilage, muscle, and nerve derivatives of the 4-6th branchial arch?

Answer 4

• Cartilage
  
  • Arytenoids, cricoid, thyroid
• Muscles:
  
  • 4^th à Cricothyroid, most pharyngeal constrictors, levator veli palatini
  • 6^th à All laryngeal muscles except cricothyroid
• Nerves:
  
  • 4^th à CN X superior laryngeal branch (swallowing)
  • 6^th à CN X recurrent laryngeal branch (speaking)

Question 5

Antibiotic associated with serotonin syndrome

Answer 5

Linezolid

MOA - inihibits 50S ribosomal subunit

Also has MAOI action

Question 6

Differences between lesions in the right vs. left frontal lobe

Answer 6

Deficits in executive functioning, concentration, orientation, judgment, personality

Left sided lesions – associated with apathy and depression

Right sided lesions – associated with disinhibited behavior

Question 7

What is HELLP syndrome

Answer 7

• Stands for:
  
  • H = Hemolysis (anemia)
  • EL = Elevated Liver enzymes (RUQ pain, jaundice)
  • LP = Low Platelets (bruising bleeding)
• Preeclampsia + thrombotic microangiopathy
  
  • Hemolysis = thrombi causing schistocytes
  • Liver enzymes = lack of RBCs leads to infarction of liver tissue
  • Platelets = all used up in thrombi

Question 8

MOA of Eptifibatide

Answer 8

• GP2b/3a antagonists
  
  • Monoclonal IgG antibody that binds GP2b/3a receptors, preventing platelet aggregation
• Sketchy = Tied game

Question 9

MOA of Ticagrelor

Answer 9

• ADP receptor antagonist – Blocks platelet ADP surface receptors (P2-Y12 receptor blocker) - prevents expression of G2b/3a and thus prevents platelet aggregation
• Sketchy: hot dog grill

Question 10

MOA of Tirofiban

Answer 10

GP2b/3a antagonists

Monoclonal IgG antibody that binds GP2b/3a receptors, preventing platelet aggregation

Sketchy = Tied game

Question 11

MOA of Abciximab

Answer 11

GP2b/3a antagonists

Monoclonal IgG antibody that binds GP2b/3a receptors, preventing platelet aggregation

Sketchy = Tied game

Question 12

What is agranulocytosis

Answer 12

Usually refers to low neutrophils

Increased risk of infection

Question 13

What are the names of the phosphodiesterase inhibitors involved in inhibiting platelet aggregation

MOA?

Answer 13

• Phosphodiesterase inhibitors à “Don’t PHOSTER DISINTEREST in sports” sign
  
  • Cilostazol = lost the ball
  • Dipyridamole = two pyramids as top of tent
• MOA:
  
  • Inhibition of phosphodiesterase leads to increases cAMP within the platelet which will activate protein kinase A, and impairing platelet function and aggregation

Question 14

Lab findings (BT, PT, PTT) + treatment in von Willebrand disease

Answer 14

• Genetic vWF deficiency
• Findings:
  
  • Increased bleeding time – decreased platelet adhesion
  • Increased PTT – vWF normally stabilizes Factor VIII
  • Normal PT
• Treatment
  
  • Desmopressin – increases vWF release from Weibel-Palade bodies of endothelial cells

Question 15

Lab findings in DIC

Answer 15

• Increased bleeding time – low platelets
• Increased PT and PTT
• Low fibrinogen – being used up
• High D-dimer (fibrin split products)
• Schistocytes

Question 16

Describe the cause + treatment of immune thrombocytopenia

Answer 16

• IgG autoantibodies to GP2b3a
• Antibodies produced by plasma cells of spleen and antibody-bound platelets consumed by macrophages of spleen
• Treatment = splenectomy

Question 17

Describe the defect in Thrombotic thrombocytopenic purpura (TTP)

Answer 17

• Platelets used up in pathologic formation of microthrombi in small vessels
• Due to decreased ADAMTS13, enzyme that normally cleaves vWF for degradation
  
  • No vWF degradation = abnormal platelet adhesion = microthrombi

Question 18

Findings in TTP vs. HUS

Answer 18

• TTP:
  
  • Findings (Pentad):
    
    • Thrombocytopenia = platelets being used up
    • Microangiopathic hemolytic anemia = RBCs sheared by microthrombi
    • Renal insufficiency (thrombi involve vessels of the kidney)
    • Neurological symptoms (confusion, HA, seizures, coma) – thrombi involve vessels of CNS
    • Fever
• HUS:
  
  • Findings (triad):
    
    • Microangiopathic hemolytic anemia
    • Renal insufficiency (thrombi involve vessels of the kidney)
    • Thrombocytopenia

Question 19

Compare the defect in Bernard-Soulier syndrome vs. Glanzmann thrombasthenia

Answer 19

• Bernard-Soulier syndrome
  
  • Defect of glycoprotein 1b
  • Platelet can’t bind to vWF on collagen = defect of platelet plug formation
  • Platelet count is only slightly low – moderate thrombocytopenia
• Glanzmann thrombasthenia
  
  • Genetic GP2b3a deficiency
  • Defect in platelet aggregation
  • Platelet count is normal (they aren’t being destroyed, just can’t aggregate)

Question 20

Describe the basic difference between Hodgkin and Non-Hodgkin lymphoma

Answer 20

Hodgkin - Rare neoplastic cells (Reed-Sternberg cells) which secrete cytokine that draw in inflammatory cells, leading to a mass

Non-Hodgkin - Whole mass composed of malignant cells

Question 21

What are the surface markers of Reed Sternberg cells

Answer 21

• Large cells with multiple/bi-lobed nuclei with clearing around the nuclei (“owl-eye”)
• RS cells are CD15+ and CD30+
  
  • THINK: 2 owl eyes x 15 = 30

Question 22

Which lymphoma is more associated with B symptoms

Answer 22

Hodgkin - Due to cytokine released by RS cells

Question 23

Most common type of Hodgkin lymphoma

Answer 23

Nodular sclerosing type

Question 24

Hodgkin lymphoma with best prognosis

Answer 24

Lymphocyte-predominant

Question 25

Describe age distribution of Hodgkin vs. Non-hodgkin lymphoma

Answer 25

* Hodgkin - bimodal distribution (peak at 20 and 65 y/o) * Think of 2 owl eyes as 2 humps * NHL - variable age range

Question 26

What is the translocation in follicular lymphoma

Answer 26

* t(14;18) = heavy chain Ig (14) and BCL-2 (18) * Overexpression of BCL-2 = decreased apoptosis * Recall that BCL2 stabilizes mitochondrial membranes, preventing leakage of cytochrome C, and thus preventing apoptosis * Follicle is where B-cells are produced, so lack of apoptosis = malignant B-cell proliferation * THNK: 18 y/o is when you can buy a gun and start killing people (apoptosis) * Apoptosis occurs in the follicle

Question 27

What lymphoma presents with "starry sky" histology

Answer 27

Burkitt lymphoma * “Starry sky” appearance – sheet of lymphocytes with interspersed “tingible body” macrophages * THINK: Burkitt = Africa - sleeping under the stars

Question 28

What is small lymphocytic lymphoma

Answer 28

Lymphoma equivalent of CLL SLL/CLL

Question 29

What diseases are associated with marginal zone lymphoma

Answer 29

* Associated with chronic inflammatory states: * Sjogren syndrome * Hashimoto thyroiditis * H. pylori * Marginal zone = area surround the mantle zone * Marginal zone is present when the cells in germinal center are activated (i.e. inflammation), so it makes sense that this lymphoma occurs in chronic inflammatory states

Question 30

What is Sezary syndrome and what do Sezary cells look like?

Answer 30

* If malignant T-cells of Mycosis fungoides leave the skin lesions and get into the blood it is called Sezary Syndrome * Sezary cells = lymphocytes with cerebriform nuclei on blood smear

Question 31

What serum markers indicate ALL

Answer 31

* TdT (+) and PAS (+)

Question 32

Translocation and surface marker associated with B-ALL

Answer 32

* CD10 (+) * t(12;21) = better prognosis * t(9;22) = poor prognosis

Question 33

Markers and histology associated with AML

Answer 33

* MPO (+) and PAS (+) * Auer rods * Crystal aggregates of MPO * Especially seen in Acute promyelocytic leukemia, AML

Question 34

Common presentation of AML

Answer 34

* DIC is a common presentation * Auer rods activate coagulation cascade

Question 35

Translocation of AML

Answer 35

* t(15;17) * Translocation of retinoic acid receptor * Think: * Auer sounds like Fuer (Hitler) – Sound of music * I am 16 going on 17 (15;17) * Poke Hitler in the eye with a carrot – treat with retinoic acid

Question 36

Common surface markers + histology of CLL

Answer 36

* 95% have B-cell markers (rather than T-cell) à CD20+ and CD5+ * Characteristic smudge cells * THINK: CLL = Crushed Little Lymphocytes = smudge cells

Question 37

What is the Richter transformation

Answer 37

* Progression of CLL to aggressive lymphoma, usually diffuse large B-cell lymphoma

Question 38

Complications of CLL

Answer 38

Recall that CLL involves mostly B-cells * Hypogammaglobulinemia * Neoplastic B-cells don’t make Ig * May cause autoimmune hemolytic anemia (both warm of cold cell agglutinins) * If neoplastic B-cells do make Ig, it will be defective and can attack the body * Richter transformation * Progression to aggressive lymphoma, usually diffuse large B-cell lymphoma

Question 39

What are the myeloproliferative disorders

Answer 39

Aka chronic leukemias of myeloid cells: - Chronic myeloid leukemia (CML) - Polycythemia vera - Essential thrombocythemia - Myelofibrosis

Question 40

Compare progression of CLL to progression of CML

Answer 40

CLL may progress to diffuse B-cell lymphoma (Richter transformation) CML may progress to AML (80%) or ALL (20%)

Question 41

Treatment of CML

Answer 41

* Responds to Imatinib (bcr-able tyrosine kinase inhibitor)

Question 42

Mutation and presentation of polycythemia vera

Answer 42

* JAK2 kinase mutation * Increased red cell mass, without elevated EPO * Presentation: * Plethora (flushed face) * Blurred vision and HA (due to hyperviscosity) * Thrombosis (e.g Budd Chiari) * Itching after bathing * Erythromelalgia (severe, burning pain and red-blue coloration in the extremities)

Question 43

Mutation and presentation of essential thrombacythemia

Answer 43

* JAK2 kinase mutation * Presentation: * Increased bleeding – dysfunctional platelets * Thrombosis – too many platelets

Question 44

What disorder presents with a "dry tap" on bone marrow aspiration

Answer 44

Myelofibrosis Hairy cell leukemia (subtype of CLL that causes marrow fibrosis)

Question 45

Mutation in myelofibrosis

Answer 45

JAK2 kinase All myeloproliferative disorders (polycythemia vera, essential thrombocythemia, myelofibrosis) except for CML have JAK2 kinase mutation

Question 46

Describe the problem in myelodysplastic syndrome

Answer 46

* Defect in cell maturation of all non-lymphoid lineages * Stem-cell disorder and dysplasia involving ineffective hematopoiesis * Cause by de novo mutations or environmental exposures

Question 47

Histology of myelodysplastic syndrome

Answer 47

* Pseudo-Pelger-Huet anomaly * Neutrophils with bilobed nuclei, connected by a thin strand * Typically seen after chemotherapy

Question 48

What disorders present with lytic bone lesions?

Answer 48

Multiple myeloma Langerhans cell histiocytosis Adult T-cell lymphoma

Question 49

Describe multiple myeloma and its classic presentation

Answer 49

* Malignant proliferation of monoclonal plasma cell within the marrow * Recall: Plasma cells = mature B-cells that produce immunoglobulin * Presentation: * Anemia – plasma cells packed in bone marrow inhibit production of other cells * Rouleaux formation of RBC * Renal insufficiency – excessive antibodies plug up kidney and form casts * Lytic bone lesions - plasma cells activate RANK * Back pain – plasma cells stimulate osteoclasts * Hypercalcemia – plasma cells stimulate osteoclasts * M spike * Increased risk of infection (monoclonal antibodies lack antigenic diversity)

Question 50

Findings in Waldenstrom macroglobulinemia

Answer 50

* B-cell lymphoma with monoclonal IgM production * Findings: * M spike due to increased IgM * Hyperviscosity: * Blurred vision * Raynoud phenomenon * Amyloidosis * No lytic bone lesions (vs. multiple myeloma)

Question 51

Describe predominant antibodies produced in multiple myeloma vs. Waldenstrom macroglobulinemia

Answer 51

Multiple myeloma = IgG and IgA Waldenstrom macroglobulinemia = IgM (thing MACRO = IgM)

Question 52

Describe presentation of monoclonal gammopathy of undetermined significance (MGUS)

Answer 52

* Monocloncal proliferation of plasma cells * Production of monoclonal immunoglobulins = M spike * No symptoms * 1-2% progress to multiple myeloma

Question 53

Presentation of Langerhans cell histiocytosis

Answer 53

* Neoplastic proliferation of specialized dendritic cells (especially in skin) * Birbeck (“tennis racket”) granules seen on EM * S-100 (+) and CD1a (+) * Presentation: * In children * Lytic bone lesions * Skin rash * Recurrent otitis media

Question 54

What is the effect of the t(9;22) translocation seen in CML

Answer 54

BCR-ABL Constitutively active tyrosine kinase)