Pathophysiology - Cancer

Breast Cancer

• Found most in upper outer quadrant of the breast
• Adenocarcinomas; most common, arise from epithelial tissues

Incidence

• Increase with age; women older than 40
• Hereditary: first degree relative with breast cancer, past breast cancer
• Menarche before age 12, menopause after age 55
• Nulliparity/parity after age 35
• High-fat diet, obesity
• Longer exposure to estrogen

Diagnostic evaluation: 

• yearly mammogram starting age 40 and continue for as long as a woman is in good health
• Clinical breast exam every 3 years in 20’s and 30’s and yearly for age 40 and over
• Monthly self-breast exam performed immediately after menstruation, use the clock to describe location of the mass

Mastectomy

• Simple mastectomy
• Removal of mammary tissue of the breast
• Partial mastectomy
• Removal of about 1/3 portion of the breast
• Radical mastectomy
• Removal of breast, pectoral muscles and axillary nodes
• Modified radical mastectomy
• Removal of breast, axillary and apical nodes and preservation of pectoral muscles
• Extended radical mastectomy
• Removal of internal mammary nodes, breast, pectoral muscles, and axillary nodes

Pathophysiology - Tissue Repair and Wound Healing

Tissue Repair and Wound Healing

• Regeneration
• Replacement of injured tissue of the same parenchymal type
• Leaves little or no evidence of injury
• Labile cells
• Continue to divide ad replicate throughout life, found in tissues with daily turnover of cells
• Surface of epithelial cells of the skin, oral cavity, vagina, cervix
• Stable cells
• Normally stops dividing when growth ceases (liver cells)
• Capable of regeneration when supporting stromal framework is present
• Permanent or fixed cells
• Cannot undergo mitotic division
• Nerves, skeletal cells, cardiac muscle cells
• Connective tissue repair
• Allows replacement of nonregenerated parenchymal cells by a connective scar tissue
• 4 Phases
• Inflammatory phase
• Hemostasis
• Activated immediately at the time of injury
• Constriction of injured blood vessel and initiation of blood clotting by platelet activation and aggregation
• Same vessels dilate and capillaries increase their permeability, allowing plasma and blood components to leak into the injured are, becomes hard
• Cellular phase
• Migration of phagocytic white blood cells that digest and remove invading organisms, extracellular debris and foreign materials
• Essential cells in the healing process
• Neutrophils or polymorphonuclear cells – day 3-4
• Macrophage – 24 hours after polymorphonuclear cells

Pathophysiology - Neoplasia / Cancer

Neoplasia / Cancer

• Results from a process of altered cell differentiation and growth
• Lacks normal regulatory control over cell growth and division

Oncology – study of tumor and their treatment

Cancer in situ – localized pre-invasive lesion depending on location

Tissue renewal and repair

• Cell proliferation
• Or the process of cell division
• Inherent adoptive mechanism for replacing body cells when old cells die or additional cells are needed
• 2 Major Categories of Cells
• Gametes (Ovum/Sperm)
• Somatic cells
• Cell differentiation
• Process of specialization whereby new cells acquire the structure and function of the cells they replace
• Fertilized ovum
• Where all of the different cell types of the body originate

Tumor / Neoplasm

• Swelling caused by inflammation or trauma

Classification

Pathophysiology - Cell Death

Cell Death

1. Apoptosis
• Involves controlled cell auto-destruction
• Means by which the boy removes and replaces cells that have been produced in excess, developed improperly, have genetic damage or worn out
• Programmed destruction of cells during embryonic development
• Example heart begins as a single pulsating tube and is gradually modified to become a 4-chambered heart
2. Necrosis
• Cell death in an organ or tissue that is still part of the living person
• Involves unregulated enzymatic digestion of cell components, loss of cell membrane integrity with uncontrolled release of the products of cell death into the intracellular spaces and initiation o inflammatory response
• Interferes with cell replacement and tissue regeneration
• Liquefication necrosis
• Occurs when some cells die but their catalytic enzymes are not destroyed
• Coagulation necrosis
• Results from hypoxic injury and in infarcted areas (tissue death)
• Caseous necrosis
• Soft, cheese-like center, associated with tubercular lesions
3. Gangrene
• considerable mas of tissue undergo necrosis
• Dry
• Part becomes dry, shrinks, skin wrinkles, dark brown or black in color
• Slow spread, line of demarcation between gangrenous and healthy tissues
• No interferes with venous return but interference with arterial blood supply

Pathophysiology - Cell Injury

Cell Injury

1. Physical Agents:
• Mechanical Forces
• Split, tear, fracture, injured blood vessels
• Extremes of temperature
• Heat – vascular injury, acceleration of cell metabolism, inactivates  temperature-sensitive enzymes, disrupts cell membrane
• Cold – increases blood viscosity, vasoconstriction, hypoxic tissue injury
• Electrical injuries
• Extreme tissue injury and disruption of neural and cardiac impulses
• Lightning: most severe damage
• Ionizing radiation injury
• Causes ionization of molecules and atoms in the cell, release of free radicals that interact with critical cell components resulting to cell death and interrupted cell replication (swelling, disruption of organelles, cell membrane alterations, marked changes in the nucleus)
• Rapidly dividing cells of the bone marrow and intestines are more vulnerable
• Skin cancer, leukemia, lung cancer
• Ultraviolet radiation
• Sunburn: increases rate of skin cancer
• Damage to melanin-producing processes on the skin
• Non-ionizing radiation
• Infrared UTZ, microwaves, laser energy
• Causes variations and rotation of atoms and molecules
• Subcutaneous tissue injury
2. Chemical injury
1. Drugs