Patho: Chapter 24 (Disorders of WBC and lymphoid tissues)

What are hematologic cancers?

Cancers that effect blood-forming tissues such as bone marrow, blood cells, and lymphatic tissues.

What are examples of hematologic cancers?

• Leukemia

• Lymphoma

• Multiple myeloma

What is hematopoiesis?

The process of producing blood cells from pluripotent stem cells in the bone marrow.

What are the components of the lymphatic system?

• Lymphatic vessels

• Lymph nodes

• Spleen

• Thymus

• Tonsils

• Bone marrow

• Lymphoid tissues

What are lymph nodes?

Small lymphatic organs that filter lymph fluid and help the immune system fight infection by housing lymphocytes and other immune cells

Where do B cells orignate and mature?

Bone marrow

Where do T cells originate and mature?

They originate in bone marrow but mature in the thymus.

What are white blood cell deficiencies?

Disorders in which the number or function of white blood cells are decreased.

What do white blood cells deficiencies cause?

They reduce the body’s ability to fight infections and weaken the immune response.

What are examples of WBC deficiencies?

• Leukopenia

• Neutropenia (agranulocytosis)

• Aplastic anemia

• Infectious mononucleosis

• HIV

What is HIV?

A retrovirus that wakens the immune system and increases susceptibility to infections.

What type of virus is HIV?

A retrovirus

What type of cells does HIV target?

T-helper (CD4+) cells of the immune system.

What causes aplastic anemia?

A disorder of pluripotent bone marrow stem cells that leads to reduced production of RBC, WBC and platelets.

What is infectious mononucleosis?

A self-limiting infectious disorder of B cells

How is infectious mononucleosis transmitted? Name a virus that causes it.

It is transmitted through saliva, often by kissing, and is caused by the Epstein-Barr virus (EBV)

Infectious mononucleosis is an infection of ______.

B cells

Why does leukemia cause bone pain and risk of fractures?

Abnormal leukemic cells overcrowd the bone marrow, damage bone marrow tissue, and lead to loss of osteocytes and osteoblasts.

What is leukemia?

A malignant cancer of blood-forming (meatopoietic) stem cells that produces abrnomal WBC in the bone marrow and blood.

What is lymphoma?

A cancer of lymphoid tissues that arises from abnormal B cells or T cells, usually in lymph nodes or other lymphatic tissues.

How is leukemia classified?

• The type of blood cell affected (lymphocytic or myelocytic/myelogenous)

• Whether the disease is acute or chronic

What is acute leukemia?

A cancer of immature blood-forming cells characterized by rapid onset, abnormal cell maturation, and aggressive progression, more common in children.

What is acute myelogenous (myelocytic) leukemia (AML)?

An acute leukemia of the myeloid cell line characterized by the accumulation of immature blood cells, impaired blood cell maturation, and pancytopenia.

What is acute lymphocytic leukemia (ALL)?

An acute leukemia of lymphoid cells, especially immature lymphocytes. Most common leukemia in children and progresses rapidly.

What is chronic leukemia?

A cancer of more mature blood cells that progresses more slowly and allows the cells to partially function, more common in adults.

What is chronic myelogenous (myelocytic) leukemia (CML)?

A chronic leukemia of the myeloid cell line characterized by abnormal proliferation of more mature blood cells. Associated with the Philadelphia chromosome, more common in adults.

What is The Philadephlia chromosome?

A chromosomal abnormality caused by a translocation between chromosomes 9 and 22. It’s associated with CML.

What is chronic lymphocytic leukemia (CLL)?

A chronic leukemia of the lymphoid cell line characterized by overproduction of abnormal B lymphocytes and slow progression usually occurs in older adults.

AML is characterized by _______________.

Abnormal and immature hematopoietic cells (lymphomas)

Which lymphoma has a higher cure rate and why?

Hodgkin lymphoma; It’s characterized by Reed-Sternberg cells, making it easier to identify and treat effectively.

What is Hodgkin lymphoma?

A specialized type of lymphoma characterized by the presence of Reed-Sternberg cells derived from B cells.

What is non-Hodgkin lymphoma?

A lympohma derived from abnormal B cells or T cells that can spread to tissues throughout the body.

In multiple myeloma, proliferation of _____ breaks down bone.

Osteoclasts

Multiple myeloma is a cancer of _________.

Plasma cells

Multiple myeloma appears to be associated with __________.

damage to DNA

All of the following are true EXCEPT:

The Reed-Sternberg cell is a sign that a person has non-hodkin lymphoma

The philadelphia chromosome causes CML.

True

Which of the following are true?

All of the above