Undifferentiated Malignant Tumours Quiz

Neoplasia 1

• Neoplasia refers to the abnormal growth of new cells.
• Neoplasm, also known as a tumour, is a mass of tissue formed due to abnormal, excessive, and uncontrolled cell proliferation.
• The new cells are distinct from normal cells, and this difference can be present even in benign neoplasms.
• Tumours can be benign or malignant.
• Benign tumours are localized, meaning they do not spread to other parts of the body, and are encapsulated by a fibrous capsule.
• Malignant tumours lack encapsulation, invade surrounding tissues, and often metastasize (spread) to different parts of the body.
• Benign tumours generally grow slowly while malignant ones grow rapidly.
• The term "tumor" is often used as a general term but not all tumours are neoplasms.

Tumor Classification

• Tumours are classified based on the cell type of origin and whether they are benign or malignant.
• Benign tumors are named with the suffix "-oma".
• Malignant tumors of epithelial origin are called carcinomas.
• Malignant tumors of mesenchymal origin are called sarcomas.
• Examples of tumor names include:
  • Lipoma: A benign tumor of fat tissue
  • Fibroma: A benign tumor of fibrous tissue
  • Leiomyoma: A benign tumor of smooth muscle
  • Melanoma: A malignant tumor of melanocytes
  • Adenocarcinoma: A malignant tumor of glandular tissue
  • Sarcoma: A malignant tumor of connective tissue

Additional Tumor Types

• Hamartoma: A mass of tissue containing normal cells, but arranged abnormally.
• Choristoma: A mass of tissue from a different part of the body present in the wrong location.

Tumor Spread

• Metastasis: The spread of cancer cells to distant sites from the original tumor.

Tumor Grading and Staging

• Grading: A measure of cellular differentiation.
• Staging: A measure of tumor size, node involvement, and metastasis.
• Higher grades indicate less differentiation from normal tissue, and are more aggressive.

Diagnostic Techniques

• Paraffin-embedding technique: A common method of preserving tissue samples for microscopic examination.
• Frozen section: A technique to obtain rapid diagnoses (e.g., margins of a surgical resection), by freezing and sectioning the tissue sample.
• Cytological methods: Examination of body fluids (e.g., urine, sputum) to detect cancer cells.
• Immunohistochemistry (IHC): A technique using antibodies to identify specific proteins within tissues, which can help determine the origin of the tumor.
• Electron microscopy (EM): A technique used for detailed analysis of tissue samples at the cellular and subcellular level, useful in cases with indeterminate cellular structures.
• Tumor markers (biochemical assays): Blood tests that can indicate the presence and extent of certain cancers.

Other Factors Affecting Tumor Development

• Age, Sex, Environmental and Cultural Factors, and familial-genetic factors.