Hematology/oncology Flashcards
How are gastrinomas diagnosed?
If serum gastrin level is >1000, it is diagnostic (should also check gastric pH because achlorhydria can cause elevated levels). If level is from 110-1000, it is non-diagnostic and a secretin stim test should be done (inhibits normal gastric G cells and stimulates release from gastrinoma cells)
What diseases are burr cells associated with?
ESRD and liver disease
What type of lung cancer is associated with parathyroid hormone-related protein (PTHrP) production?
Squamous cell carcinoma
What is Waldenstrom macroglobulinemia?
Lymphoplasmocystic malignancy characterized by excessive production of monoclonal IgM. Elevated IgM leads to hyperviscosity syndrome (diplopia, tinnitus, headache, dilated/segmented funduscopic findings), neuropathy, cryoglobulinemia. Neoplastic infiltration of tissue causes hepatosplenomegaly, lymphadenopathy, and cytopenias. Peripheral smear may show rouleaux formations. Dx confirmed by bone marrow biopsy showing >10% clonal B cells.
What are signs and symptoms of polycythemia vera?
Increased blood viscosity leading to HTN, erythromelalgia (burning cyanosis in hands/feet), and transient visual disturbances. Increased RBC turnover can cause gouty arthritis. Pruritus in hot water, facial plethora, splenomegaly, and bleeding.
How is polycythemia vera treated?
Serial phlebotomy. Can add hyroxyurea (bone marrow suppression) if increased risk for thrombus
What are complications of polycythemia vera?
Thrombosis, myelofibrosis and acute leukemia
How are EPO levels affected by polycythemia vera?
Low. Caused by JAK2 mutation, not EPO
What type of tumor produces beta-hCG and AFP?
A nonseminomatous germ cell tumor.
Note that both seminomatous and nonseminomatous germ cell tumors produce beta-hCG, but only nonseminomatous produce AFP.
What is the treatment of choice for CNS lymphoma?
High-dose methotrexate. Also responds to whole brain radiation
What coagulopathy is a common cause of a false positive VDRL?
Antiphospholipid antibody syndrome
How does thyroid lymphoma present?
Often in patients with Hashimoto thyroiditis though very rare. Presents as a rapidly enlarging, firm goiter associated with compressive symptoms (e.g. dysphagia, hoarseness). May also have systemic B symptoms. If extends into the retrosternal space, can compress vascular structures leading to distended neck veins and facial plethora
How does a cardiac myxoma present?
80% are located in L atrium. Get constitutional sx of fever, weight loss, and possible Raynaud phenomenon. Can lead to mitral disease and heart failure. Can even invade into lung parenchyma causing respiratory sx.
What is Trousseu’s syndrome and what is associated with?
Migratory superficial thrombophlebitis. Associated with an occult visceral malignancy: pancreatic is most common but also lung, prostate, stomach, and colon cancer and acute leukemias
What vitamin deficiency may result from carcinoid syndrome?
Niacin deficiency. Both serotonin and niacin use tryptophan as a precursor so advanced carcinoid syndrome can deplete tryptophan
What lab test can help differentiate chronic myeloid leukemia from a leukamoid reaction?
The leukocyte alkaline phosphatase score (low=CML, high=leukamoid)
What cancer are patients with pernicious anemia at risk for?
Gastric cancer - leads to chronic atrophic gastritis which puts patients at risk for developing gastric malignancy
What are the colonoscopy guidelines for patients with familial adenomatous polyposis?
Start at age 10-12 and get annually
What are the colonoscopy guidelines for patients with HNPCC (Lynch syndrome)?
Start at age 20-25 and repeat every 1-2 years
What are clinical features of paroxysmal nocturnal hemoglobinuria?
An autoimmune hemolytic disorder characterized by intra and extravascular hemolysis and hemoglobinuria. Due to an acquired genetic defect leading to lack of CD55 and CD59 which protect the cell from complement and MAC
–> hemolysis. Pts have a tendency towards venous thromboembolism. On average patients manifest with symptoms in the fourth decade of life and will classically have fatigue, hemolysis, cytopenias, and venous thrombosus.