Introduction to Pathology

Introduction to Pathology

• Pathology is the study of disease, encompassing the structural, functional, and biochemical changes in the body due to disease processes.
• It includes the study of disease causes, mechanisms, and consequences.
• Pathology is crucial for disease diagnosis, prognosis, and treatment.

Neoplasia - Overview

• Neoplasia is abnormal cell growth, often uncontrolled.
• It can be benign (non-spreading) or malignant (spreading).
• Uncontrolled cell growth forms tumors.
• Benign tumors do not spread, malignant tumors can.

Benign Tumors

• Benign tumors grow slowly and locally.
• They are usually encapsulated, preventing spread.
• Benign tumors usually don't cause significant harm unless they press on vital structures.
• Benign tumors rarely cause death.
• Benign tumors lack the ability to metastasize.

Malignant Tumors (Cancer)

• Malignant tumors are aggressive and spread.
• They lack encapsulation, frequently infiltrating tissues.
• They arise from multiple genetic mutations causing uncontrolled growth.
• Spreading creates secondary tumors (metastases), affecting survival.
• Malignant transformation involves genetic predispositions, environmental exposures, viral infections, and immunodeficiency.

Characteristics of Malignant Neoplasms

• Malignant tumors (cancers) are aggressive and metastasize.
• They exhibit rapid growth and tissue invasion.
• They have atypical cell morphology and a loss of differentiation.
• They have accelerated cell cycle activity.

Types of Neoplasms

• Neoplasms are classified by tissue of origin and tumor characteristics.
• They include carcinomas (epithelial), sarcomas (mesenchymal), leukemias and lymphomas (hematopoietic), and others.
• Cancers have diverse growth rates, prognoses, and responses to therapies.

Diagnosis and Staging of Neoplasia

• Neoplasia diagnosis involves histological examination of tissue samples (biopsies).
• Pathologists analyze tissue samples microscopically to determine cell morphology in order to diagnose benign or malignant conditions.
• Cancer stage indicates disease extent in the body, guiding prognosis and treatment.

Factors Affecting Neoplasia

• Environmental factors (carcinogens, smoking, UV radiation) increase neoplasia risk.
• Genetic factors (inherited mutations) increase some neoplasia risk.
• Lifestyle factors (diet, exercise) may influence some cancers.

Treatment of Neoplasia

• Cancer treatment varies by cancer type, stage, and patient.
• Treatments include surgery, radiation, chemotherapy, and targeted therapies.
• Immunotherapy is a newer, promising treatment approach.

Tumor Grading and Staging

• Tumor grading assesses the degree of differentiation.
• Tumor staging evaluates the extent of cancer spread.
• These evaluations are essential for prognosis and treatment decisions.