NH2

NH2

1. Neoplasia

   • Benign
     • Grow as a compact mass within the tissue as they expand.
     • Do not metastasise
     • Expansive (benign epithelial tumours form polyps). May cause obstruction if large enough
     • Histologically closely resemble parent cell
     • Growth rate relatively low (few mitotic cells)
     • Encapsulated, non-invasive, rarely lethal
     • Cause pressure atrophy of the surrounding parenchymal tissue - benign meningeal tumour causing epilepsy.
     • May cause excessive production of hormones
   • Malignant
     • Invasion of the surrounding tissue as they grow and may spread to distant sites
     • Grow in an irregular pattern into the surrounding tissue
     • Spread (metastasise) - access the lymphatic or blood vessels and are then carried to a distant site
       • NP cell invasion of surrounding tissue
       • Embolization
         • Even though malignant neoplastic cells invade lymphatic and blood vessels and enter the circulation, only an extremely small number of embellished cells establish metastatic lesions
       • Extravasation
         • Lodging of immobilised cells in the small vessels such as capillaries or lymphatic vessels. Then, adhere to endothelial cells, migrate into the wall and degrade the matrix, enter the tissue and form a metastatic tumour in the tissue
       • Routes of Metastasis
         • Blood
           • to bone
           • to liver, lungs and brain
           • Not to skeletal muscle or spleen
         • Lymph
           • to lymph nodes causing poor drainage and oedema of the surrounding tissue
         • Transcoelomic
           • Effusion of fluid into the peritoneal, pleural, and pericardial cavities
           • Periotoneal effusion (ascites): ovarian cancer
           • Pleural and Pericardial: Breast and Lung
     • Considerable mortality and morbidity
       • Destruction of adjacent tissue
       • Formation of secondary tumours
       • Blood loss from ulcerated surfaces
       • Pain
       • Obstruction of flow
       • Inappropriate production of hormones
     • Poorly circumscribed - stand of NP tissue extend into the normal tissue
     • Histologically less resemblance of parent cell
     • Often have central necrosis - surfaces are often ulcerated
     • Not-encapsulated, high growth rate, invasive, metastasise, often lethal
     • Treatment Options
       • Surgery
       • Radiotherapy
       • Chemotherapy
   • Abnormal tissue with excessive autonomous (new) growth uncoordinated with normal tissue
   • Lack normal negative feedback mechanism to arrest cellular proliferation
   • Arise from the clonal expansion of a single cell that has undergone neoplastic transformation (mutation)
   • Cells immortally proliferate
   • Result in large numbers of one cell type in a location (focus): tumour mass, often anatomically innappropriate
   • May result in the expression of characteristics to the mature differentiated cell (e.g. secretion of metal proteins (alpha-fetoprotein, CEA))
   • Abnormal relationship between the NP cells and the normal tissue surrounding them: uncontrolled growth (lack of appropriate cell-cell communication), recruitment of the surrounding tissue to provide nutrients/O2 (angiogenesis).

2. Classifying Neoplastic Tumours

   • Aetiology (cause)
   • Organ of Origin
   • Biological Behaviour
   • Histo/Cyto-Genesis
     • Epithelial tissue: Carcinoma
       • Protective
         • Benign: Papilloma
         • Squamous cell carcinoma
       • Basement
         • Malignant: Basal cell carcinoma
       • Secreting
         • Benign: Adenoma
         • Malignant: Adenocarcinoma
     • Stromal (connective/supportive tissue): Sarcoma
       • Fibrous
         • Benign: Fibroma
         • Malignant: Fibrosarcoma
       • Nerve Sheath
         • Malignant: Neurofibrosarcoma
         • Benign: Neurofibroma
       • Adipose
         • Malignant: Liposarcoma
         • Benign: Lipoma
       • Smooth Muscle
         • Malignant: Leiomyosarcoma
         • Benign: Leiomyoma
       • Striated Muscle
         • Benign: Rhabdomyoma
         • Malignant: Rhabdomyosarcoma
       • Cartilage
         • Benign: Chondroma
         • Chrondrosarcoma
       • Bone (osteoblast)
         • Benign: Osteoma
         • Malignant: osteosarcoma
     • Lymphoid/Haemopoietic
       • Malignant Lymphoma: Hodgkin's Disease
       • Multiple Myeloma: Leukaemia
     • May be difficult to assign categories
     • Germ Cell NP
       • Malignant - Men: Seminoma+Non-Seminoma
       • Benign - Women: Mature Cystic Teratoma
     • Blastoma - occur in children less than 5 years old

3. Staging Malignant Tumours

   • The spread determines the stage

4. Grading Malignant Tumours

   • The degree to which the NP resembles the tissue of origin determines the grade
   • Well-differentiated: looks similar to parent tissue
   • Moderately differentiated: looks something like normal
   • Poorly differentiated: hardly looks normal
   • Anaplastic: virtually no similarity to normal
   • The higher the grade, the lesser the degree of differentiation, and the worse the biological behaviour of the malignant NP will be
   • Grading acts as a proxy for info on aggressiveness

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