Neoplasms - VO 2

Neoplasms

  • Neoplasia: Refers to cancer; characterized by non-adaptive, abnormal cell growth.

  • Key Characteristics:

    • Loss of apoptosis (programmed cell death).

    • Not stimulated growth; abnormal differentiation.

    • Cells no longer resemble parent cells and serve no purpose, utilizing body resources.

Types of Neoplasms

  • Benign Tumors:

    • Remain localized; do not spread.

    • Grow slowly, expanding mass, encapsulated.

    • Cells similar to normal cells; differentiated.

  • Malignant Tumors:

    • Capable of metastasis (spreading to distant sites).

    • Invasive with rampant growth, larger, often irregular cancerous cells.

Characteristics of Benign vs. Malignant Tumors

Benign Tumors:

  • Similar to normal cells.

  • Differentiated, mitosis is fairly normal.

  • Typically slow-growing, encapsulated, remains localized.

  • Rarely life-threatening.

Malignant Tumors:

  • Abnormal, varied size and shape.

  • Many undifferentiated cells, increased and atypical mitosis.

  • Rapid growth, not adhesive, can infiltrate nearby tissue and metastasize.

  • Often life-threatening and systemic effects present.

    • Lack a capsule, irregular shape, may invade nearby tissues.

Warning Signs of Cancer

  1. Unusual bleeding or discharge.

  2. Changes in bowel or bladder habits (prolonged diarrhea, discomfort).

  3. Changes in warts or moles (color, size, shape).

  4. Non-healing sore anywhere on the body.

  5. Unexplained weight loss.

  6. Anemia or low hemoglobin; persistent fatigue.

  7. Persistent cough or hoarseness without cause.

  8. A painless lump in the breast, testes, or anywhere on the body.

Local Effects of Tumors

  • Pain:

    • Often absent until late stages; severity varies with tumor type.

  • Obstruction:

    • Tumors may compress ducts or passageways (e.g., digestive tract).

  • Tissue Necrosis and Ulceration:

    • Can lead to bleeding or infections around the tumor.

Systemic Effects of Malignant Tumors

  • Weight Loss and Cachexia:

    • Anorexia, fatigue, increased energy demands on the body.

  • Anemia:

    • Caused by blood loss and nutritional deficits.

  • Severe Fatigue:

    • Linked to inflammation, anemia, the stress of treatment.

  • Effusions:

    • Inflammation causes fluid buildup in body cavities.

  • Infections:

    • Frequent due to lowered resistance.

  • Bleeding:

    • Tumor cells erode blood vessels.

  • Paraneoplastic Syndrome:

    • Tumor cells release substances affecting neurological/hormonal functions.

Diagnostic Tests for Cancer Detection

  • Routine Screening: Important for early detection.

  • Self-Examination: For breast, testicular, and skin.

  • Blood Tests: Measure blood cell levels and detect tumor markers (e.g., PSA).

  • Radiographic Techniques: Ultrasound, MRI, CT for tissue changes.

  • Cytological Tests:

    • Require biopsies; helps in determining tumor type and differentiation.

Spread of Malignant Tumors

  • Invasion:

    • Local spread due to tumor cell growth into adjacent tissues (example: uterine carcinoma).

  • Metastasis:

    • Spread to distant sites using blood or lymph (example: colon carcinoma to liver).

Staging Cancer

  • Essential for treatment comparison and prognosis assessment.

  • Commonly uses TMN System:

    • T = Size of primary tumor.

    • N = Regional lymph node involvement.

    • M = Metastasis extent.

Carcinogenesis Process

  • Transformation of normal cells into cancer cells.

  • Influenced by:

    • Environmental factors.

    • Genetic changes.

    • Infections (e.g., cervical, hepatic cancers).

  • Recognizing well-established risk factors is critical.

Cancer Risk Factors

  • Genetic Factors: Oncogenes that regulate growth.

  • Viruses: Oncoviruses modify host DNA.

  • Radiation:

    • Ultraviolet rays, X-rays, radioactive isotopes; risk increases with dosage.

Cancer Incidence by Gender

  • Men Most Common:

    • Prostate, lung, colorectal cancers.

  • Women Most Common:

    • Breast, lung, colorectal cancers.

Intracellular Accumulation

  • Substance buildup in cells due to inefficiency in usage or disposal.

  • May be reversible if the stimulus is removed; lethal if not.

  • Accumulations can be cytoplasmic or nuclear, seen in conditions such as:

    • Black Lung Disease: Carbon buildup in the lungs.

    • Tay-Sachs Disease: Lysosomal storage disorder.

    • Accumulations include water, lipids, carbohydrates, proteins, pigments, calcium, urate.

Conclusion

  • Understanding neoplasms and their impacts is crucial for diagnostics, treatment, and patient outcomes.