Heme/Onc Flashcards
Osler-Weber-Rendu syndrome
Hereditary hemorrhagic telangectasias resulting in epistaxis and widespread AVMs.
How can AVMs in the lung cause reactive polycythemia?
They mix deoxygenated blood with arterial blood and cause chronic hypoxemia, EPO release and reactive polycythemia.
Young woman has an expansile eccentrically lytic area at the distal edge of her femur. Biopsy shows sheets of interspersed large round to oval polygonal mononuclear cells.
Giant cell tumor
Osteitis fibrosa cystica (Von Recklinghausen disease of the bone)
Parathyroid carcinoma results in hyperparathyroidism, bone resorption and subperiosteal bone resorption causing brown tumors of the skull, fingers and long bones.
Sclerotic cortical punched out bone lesions with central lucency in a kid with bone pain worse at night relieved by NSAIDs.
Osteoid osteoma
Classic tetrad of multiple myeloma
“CRAB”
Hypercalcemia
Renal failure
Anemia
Bone pain
Paraprotein gap
Normal is 3-4, significant when > 4
Clinical manifestations of polycythemia vera
Hypertension, plethora, peptic ulcers (basophils release more histamine) and gouty arthritis (increased cell turnover).
Polycythemia treatment
Phlebotomy to keep Hct
Best treatment for bone pain in patients with prostate cancer
XRT
Flutamide
DHT receptor antagonist used in prostate cancer in combination with LHRH agonists.
Drugs that commonly trigger hemolysis in patients with G6PD deficiency
Dapsone, primaquine and TMP-SMX
When to screen for G6PD deficiency in a patient with recent hemolytic reaction to TMP-SMX?
3 months after the episode because the RBCs with the deficient enzyme are likely gone initially.
Most common cause of B12 deficiency? Associated risk?
Pernicious anemia…increased risk of gastric cancer.
Drugs of choice to stabilize bony mets and reduce hypercalcemia?
Bisphosphonates
Treatment of patients with isolated severe thrombocytopenia after a viral infection?
ITP is due to IgG antibodies against the platelet membrane and can be treated with IVIg or glucocorticoids if there is bleeding in children or platelets
Bernard-Soulier syndrome
AR deficiency in GpIb on platelets that prevents them from binding vWF.
Leukemoid reaction vs. myeloid leukemia
Leukemoid reaction has high LAP activity, WBC > 50k, more metamyelocytes and bands and lack of absolute basophilia.
Myeloid leukemia has WBC > 100k, more myelocytes and absolute basophilia.
Metabolic abnormalities seen in tumor lysis syndrome
Increased intracellular ions: hyperphosphatemia and hyperkalemia. The phosphate binds Ca and causes hypocalcemia. Degraded cell proteins causes hyperuricemia.
Condition where patients with sickle cell disease can no longer concentrate their urine due to RBC sickling in the vasa recta in the inner medulla. This disrupts counter current exchange and limits concentrating ability.
Hyposthenuria
Likely cause of pancytopenia in a patient with lupus
Immune-mediated destruction of cells in all 3 lines
SPEP in patients with multiple myeloma
M-spike due to increased IgG
Non-megaloblastic macrocytic anemias
EtOH, hypothyroid, liver disease and drugs
Cofactors to give a patient if they present with recurring DVT in the face of elevated homocysteine
B6 is necessary for the conversion of homocysteine to cystathione. Folate is necessary for conversion of homocysteine to methionine.
What about the spleen makes it necessary for immunity against encapsulated bacteria?
The bacteria enter the spleen and are phagocytosed by dendritic cells in the white pulp. These dendritic cells process the capsule and present it on MHC II to CD4+ T-cells which then migrate to the marginal zone to activate B-cells in primary follicles. This causes secondary follicles and germinal centers to form where these B-cells will crank out antibodies against the capsular antigen.
Next step if smudge cells are seen on blood smear of a patient with elevated WBC and predominate lymphocytes.
Flow cytometry to confirm clonality of the lymphocytes and diagnose CLL.
Pentad of TTP
Thrombocytopenia, hemolytic anemia, fever, renal failure and altered mental status.
A patient has a DVT and wants rivaroxaban instead of warfarin. How do you council him regarding this decision?
The biggest drawback is there is no reversal agent for factor Xa inhibitors like rivaroxaban, where with warfarin you can give FFP. Other than that its way better because it starts working within 2-4 hours, doesn’t require heparin overlap or INR monitoring.
Why supplement folate in patients with sickle cell anemia?
They are chronically hemolyzing and have increased cellular synthesis compared to the average person’s bone marrow.
Why alcoholics are at risk for folate deficiency?
EtOH disrupts enterohepatic recycling of folate and limits folate absorption
Infections to check patients for when presenting with new ITP
EBV, HIV and HCV
Treatment of patients with TTP-HUS
Plasmapheresis to remove anti-ADAMTS13 antibodies that prohibit cleaving vWF multimers.
When is transfusion indicated in patients with CAD or CHF?
Hgb
Leukemia that may frequently present with a dry marrow tap. Markers?
Hairy cell. CD11c + and TRAP +
Recommended testing in patients with 1st unprovoked DVT?
Age-appropriate screening + CXR
MGUS vs. Waldenstrom’s macroglobulinemia
MGUS = asymptomatic Waldenstrom's = symptoms secondary to hyper viscosity and IgM spike on SPEP
What patients are candidates for EPO?
CKD with Hct
Most common side effects of EPO therapy?
HTN, HA, flu-like symptoms and red cell aplasia.
Easy way to correct the anemia in a patient with microcytic anemia, normal iron studies and ringed sideroblasts on peripheral smear?
Rule out B6 deficiency from alcoholism, isoniazid or other drugs as the cause of sideroblastic anemia.
Diagnostic criteria for antiphospholipid antibody syndrome
Need 1 clinical and 1 lab criteria:
Clinical: thrombosis, ≥3 unexplained fetal losses before 10 weeks, ≥1 after 10 weeks, ≥1 preemie b/f 34 weeks due to pre-E, eclampsia or placental insufficiency.
Lab: lupus anticoagulant (PTT prolongation), anti-cardiolipin antibodies, anti-b2GP1 antibodies
Specific tests for the lupus anticoagulant
Russel viper venom test and the kaolin clotting time
Drugs that can cause megaloblastic anemia via folate deficiency?
Reduced GI absorption: Phenytoin, primidone, phenobarbital
Inhibits dihydrofolate reductase: TMP-SMX and MTX
Mutation present in >95% of patients with polycythemia vera?
JAK2
Manifestations of paroxysmal nocturnal hemoglobinuria?
Absence of CD55 and CD59 due to deficiency in glycosylphosphatidylinositol membrane anchor results in complement MAC formation, causing hemolysis, cytopenias and hypercoaguability (portal vein thrombosis)
Thalassemia that will show an abnormality on Hgb electrophoresis?
Beta-thal minor will show increased HbA2. Alpha-thal minor will not show any abnormality.
Meds used to increase appetite in cachectic cancer patients?
Megestrol acetate (progesterone analogues) can increase appetite and are preferred over corticosteroids. Synthetic cannabinoids are better for HIV-associated cachexia.
Ways to confirm diagnosis of hereditary spherocytosis
Osmotic fragility test
Eosin-5-maleimide test
Drug of choice for hairy cell leukemia
Cladribine, a purine analogue toxic to bone marrow.
Drugs of choice for CLL
Chlorambucil and prednisone
Drugs of choice for non-Hodgkin’s lymphoma
CHOP
Methods of reducing sepsis in patients undergoing splenectomy
Immunize against s. pneumo, n. meningitides and h. influenzae ≥14 days before the operation. May also consider lifetime PCN prophylaxis.
Pathophysiology behind CML vs. leukemoid reaction
CML = BCR-ABL fusion t(9;22) leading to constitutively active tyrosine kinase (this is why tyrosine kinase inhibitor like imatinib treat the disease)
Leukemoid reaction = infection
