Hematological Malignancies and Cancer Basics

Hematological Malignancies

• Cancer is defined as uncontrolled cell growth with loss of apoptosis (programmed cell death).
• Cancer can occur in any cell in the body, and when it occurs in blood cells, it is known as either Leukemia (from myeloid or lymphoid cells), Lymphoma (from lymphoid tissue), or Myeloma (from plasma cells).

Leukemia

• Leukemia is classified into acute (rapid progression) and chronic (slow progression) types.
• Acute Leukemia:
  • Can be myeloid (AML) or lymphoid (ALL)
  • Epidemiology: generally affects older people, non-Hispanic whites, and those with genetic disorders, radiation exposure, or chemical exposure
  • Signs and symptoms: fatigue, anemia, high white cell count, bleeding/bruising, bone/joint pains, skin manifestations, and pallor
  • Acute Leukemia cells are "sticky" and can cause hyperviscosity, making it a medical emergency
  • Treatment: chemotherapy (unless palliative care) and specialized treatment for Acute Promyelocytic Leukemia (APML)
• Chronic Leukemia:
  • Chronic Myeloid Leukemia (CML): characterized by Philadelphia chromosome translocation BCR-ABL t(9;22), exposure to ionizing radiation is a risk factor, and treatment involves tyrosine kinase inhibitors
  • Chronic Lymphoid Leukemia (CLL): affects older people, smudge cells are present, and treatment involves new drugs in pill form

Lymphomas

• Epidemiology: relatives of probands have a 3.5x higher chance of developing lymphoma, higher incidence in people with RA, hemolytic anemia, Crohn Disease, and motor and Celiac disease
• Hodgkin Lymphoma:
  • Peak incidence at young ages (20-24) and old ages (80-84)
  • Presents with lymphadenopathy, fatigue, and pruritus
  • Treatment: complex chemotherapy, radiation therapy, or a combination of both, and BMT or CART therapy
• Non-Hodgkin Lymphoma:
  • Affects all races, ages, and socioeconomic status
  • Presents with lymphadenopathy, fever of unknown origin, and can be associated with immunodeficiencies
  • Diagnosis: excisional biopsy of the LN (FNA's are notoriously poor), and CBC for anemia, thrombocytopenia, and abnormalities of the WBC count

Plasma Cell Dyscrasias - Multiple Myeloma (MM)

• Multiple Myeloma:
  • Epidemiology: higher incidence in African Americans, increases with Body Mass Index, and association with agent orange exposure
  • Symptoms: mild back pain, anemia, renal insufficiency, and bone disease
  • CRAB criteria: calcium deviation, renal insufficiency, anemia, and bone disease
  • Pitfalls: worsening hypercalcemia, increased thirst and urination frequency, confusion, and bone lesions with pathological fractures
  • Treatment: induction chemotherapy, autologous transplant, and maintenance therapy (no cure, only prolongs survival)

Myelodysplastic Syndrome (MDS)

• MDS is a premalignant disorder that will be cancer if left untreated
• Defined as a pre-malignancy of the bone marrow

This quiz covers the general concepts of cancer, including uncontrolled cell growth, apoptosis, and types of hematological malignancies such as leukemia, lymphoma, and myeloma. Review of marrow components is also included.