Neoplasia Overview and Classification

Neoplasia

• Uncontrolled cell proliferation, even without an irritant factor
• Caused by regulatory mechanisms failure
• Consists of parenchyma (neoplastic cells) and stroma (supporting tissue)
• Diagnosed through physical exams, imaging, and biopsies/autopsies
• Risk factors are sporadic, familial, or genetic
• High risk of malignancy associated with BRCA1/2 and P53

Benign Neoplasia

• Well-differentiated cells resembling original tissue
• Slow growth, non-aggressive
• Well-defined borders, often encapsulated
• Non-metastasizing (does not spread)
• Can cause compression of surrounding tissues and endocrine dysfunction.

Malignant Neoplasia

• Poorly differentiated cells, only slightly resembling original tissue
• Fast growth, aggressive
• Poorly defined borders, non-encapsulated
• Metastasizes (spreads) via lymph, blood, or body cavities
• Destructive local infiltration

Metastasis

• Spread of malignant cells to distant organs or tissues
• Frequently targets organs with high blood flow (liver, lungs) and bone marrow
• Can spread to unusual locations, like heart, brain, or other areas

Local Malignant Neoplasia

• Non-metastasizing but destructive to local tissue
• Example: basal cell carcinoma (common skin cancer)

Dysplasia

• Disrupted epithelial architecture due to chronic stress
• Reversible if the stress is removed, otherwise can progress to neoplasia
• Characterized by abnormal cell shapes, sizes, and loss of tissue orientation
• Increased nuclear-cytoplasmic ratio and clumped chromatin

Grading

• Categorizes tumors based on differentiation and architecture
• Better differentiation tends to have a better prognosis
• G1 (well-differentiated) is more resistant to chemotherapy
• G4 (anaplastic) is often more aggressive

Staging

• Evaluates tumor clinical advancement for appropriate treatment
• Indicator for prognosis and treatment efficacy
• TNM system to assess tumor size, lymph node involvement, and metastasis

Tumor Nomenclature

• Carcinomas: malignant epithelial tumors
• Derived from various tissues (e.g., squamous, glandular)
• Sarcomas: malignant mesenchymal tumors
• Derived from connective tissue elements
• Benign tumors named by tissue of origin + "-oma" suffix

Dysplasia Grading

• Mild/moderate: reversible, does not involve entire epithelium
• Severe: irreversible, involves entire epithelium thickness

Ovarian, Lung, Gastric Neoplasms

• Specific types of cancers with varying grades and stages (e.g., ovarian serous, lung squamous, gastric adenocarcinoma)
• Diagnosed with various methods (e.g., imaging, biopsies)
• Treatment options are specific to each type

Prophylaxis of Cancer

• Primary prevention involves modifying lifestyle factors (weight, exercise, no smoking)
• Secondary prevention involves early detection through screening tests (Pap smear, mammogram)

Paracancerous Syndromes

• Syndrome of clinical symptoms not related to tumor spread
• Associated with substance secretion from tumor cells
• Commonly linked to lung, breast, leukemia, and lymphoma cancers.

Carcinogens

• Agents that cause genetic damage leading to transformation
• Can be divided into direct-acting (immediately modify DNA) and indirect-acting (requires metabolic conversion)
• Include alkylating agents, tobacco, asbestos, alcohol, aflatoxin, aromatic amines, physical radiation, and certain viruses

Oncogenic Viruses

• Viruses linked to cancer development
• Can integrate their DNA into the host genome
• Including Human T-cell Leukemia Virus (HTLV-1), Epstein-Barr Virus (EBV), Hepatitis B Virus (HBV), Hepatitis C Virus (HCV), and Human Papillomavirus (HPV)

Tumor Suppressor Genes

• Inhibit cell proliferation to prevent uncontrolled growth
• Abnormalities lead to cancerous growth
• Includes tumor suppressor genes such as p53, RB, BRCA1/2, and APC

Pre-neoplastic Diseases

• Diseases that increase cancer risk,
• Can be identified through various screening and diagnostics,
• include various factors such as inflammation & hormonal imbalances.

Explore the essential concepts of neoplasia, including the differences between benign and malignant neoplasia. Understand the characteristics, diagnosis methods, and implications of metastatic spread. This quiz will enhance your knowledge about cell proliferation and cancer risk factors.