oncology / hematology

hematopoiesis

process of blood formation

where does hematopoiesis occur?

primarily in bone marrow

what stimulates rbc production

• hypoxemia

• blood loss

what is necessary for development of rbcs? (4)

• cytokines

• iron

• vitamin B12

• folate

what occurs with hemoglobin production when iron is low

low iron = less hemoglobin = less oxygen carrying potential

anemia causes

• blood loss

• impaired rbc production

• increased destruction of rbc

what is mean corpuscular volume

indicates the average size of a person’s rbc

what is mean corpuscular hemoglobin

measures the average amount of hemoglobin within a rbc

normal size 

normocytic

normal color

normochromic

large size

macrocytic

small size

microcytic

pale color

hypochromic

normocytic, normochromic anemia

caused by:

• acute blood loss

• hemolysis

• chronic renal disease

• cancer

• diabetes

• aplastic anemia

macrocytic, normochromic anemia

normal hgb as rbcs are not pale, become big as there is a lack of vit B12 (no dna synthesis, cells not dividing)

caused by:

• B12 deficiency

• folate deficiency

• liver disease

microcytic, hypochromic anemia

caused by:

• iron deficiency anemia

• thalassemia

• lead poisoning

aplastic anemia

a condition where bone marrow stops making enough new blood cells

thalassemia

genetic blood disorder where the body makes abnormal hemoglobin

iron deficiency anemia

results when there is inadequate iron supply for hemoglobin production

• characterized by small, pale rbcs

what populations are iron deficiency anemia most common in?

• young children (<2)

• women in reproductive years

• diets that are not nutritionally adequate

signs and symptoms of iron deficiency anemia

• pale skin + mucous membranes

• fatigue / lethargy

• depression, muscle aches

• dyspnea, tachycardia

• brittle, spoon-shaped nails (koilonychia)

• decreased appetite, pica

sickle cell disease

an inherited blood disorder where the body produces abnormal hemoglobin called “HbS” 

• under low oxygen conditions (cold exposure, dehydration, infection, etc) rbcs change to a rigid, sickle shape that obstruct capillaries and become sticky

• this causes a vasocclusive crisis

sickle cell crisis

• tissue ischemia and pain

• with reoxygenation cells return to normal

lifespan of sickled cells

10-20 days

inheritence of sickle cell disease

• both parents must be a carrier

• most carriers are asymptomatic

preventon of sickle cell crisis

• avoid hypoxia

• encourage hydration

• avoid cold exposure, infection, stress

• vaccination

• prophylactic penicillin in children until age 5

disease modifying therapies for sickle cell anemia

• hydroxyurea: increases fetal hemoglobin, reduces sickling and pain crisis

• bone marrow transplant

triggers for sickle cell crisis

• infection

• dehydration

• stress

• cold exposure

leukemia

cancer of the blood cells that usually starts in the bone marrow and travels through the blood stream

• overproduction of blast cells. immature blood cells are not differentiating into rbcs, platelets, neutrophils, etc.

types of leukemia

• acute lymphoblastic leukemia (ALL)

• acute myelogenous leukemia (AML)

• chronic (CLL and CML)

difference = whether its the lymphoid or the myeloid stem cells becoming malignant

signs and symptoms of leukemia

• fever

• bleeding

• lethargy

• anorexia

• petechia

diagnosis of leukemia

bone marrow aspiration is the only way to fully diagnose leukemia

expected abnormal labs for leukemia

• low platelets

• low hemoglobin

• elevated wbcs

• presence of blast cells

risk levels for ALL (5)

standard risk:

• child between ages of 1 and 10

• when dx, had less than 50,000 wbc

• no blast cells in csf

high risk:

• age of less than 1 or older than 10 at time of dx (rapid times of growth)

• when dx, more than 50,000 wbcs

• leukemic cells in csf

• testicular involvement

• if steroids were given before dx

how long is treatment for ALL?

2-3 years

febrile neutropenia

• abnormally low number of neutrophils

• fever greater than 38.3 c or greater than 38 for more than 1 hour

• medical emergency

lymphoma

• the uncontrolled growth of abnormal lymphocytes

• can oringate in any part of the lymphatic system (lymph nodes, spleen, etc)

• cancerous lymphocytes can travel through the blood and spread to many parts of the body

hodgkin’s lymphoma

• B lymphocytes only

• more localized

• B symptoms common

• confined mostly to lymph nodes

• characterized by reed-sternberg cells

causes of lymphoma

• epstein-barr virus

• genetic predisposition

• exposure to toxins

• HIV

non-hodgkin’s lymphoma

• B lymphocytes and T or natural killer lymphocytes

• more widespread

• B symptoms uncommon

• extranodal involvement common (tumors outside lymph nodes)

B symptoms lymphoma

• fever

• night sweats

• weight loss

lymphoma symptoms

• enlarged lymph node

• weight loss

• fatigue

• weakness

• fever and chills

• tachycardia

• night sweats

• alcohol intolerance

diagnosis of lymphoma

• microcytic anemia

• neutrophil leukocytosis

• increased platelets

• lymph node biopsy

• bone marrow biopsy

• CT or MRI for staging

lymphoma staging

• stage I: involvement of single lymph node

• stage II: involvement of 2 or more lymph nodes above diaphragm

• stage III: lymph node involvement above and below diaphragm

• stage IV: involvement outside the lymph nodes

treatment for lymphoma

• ABVD regimen - doxirubicin (adriamycin), bleomycin, vinblastine, dacarbazine

• stem cell transplant

tumor lysis syndrome

• oncological emergency

• rapid destruction of tumor cells and tumor contents get released into bloodstream

• can cause hyperkalemia, hyperuricemia, hyperphosphatemia, and hypocalcemia

symptoms of tumor lysis syndrome

• nausea

• vomiting

• diarrhea

• muscle cramps + twitches

• confusion

• seizures