Benign vs Malignant

Benign vs Malignant

1. Benign

2. Malignant

3. 1. Differentiation/anaplasia

   • Functionality of parenchymal components
   • Benign
     • 1. Well differentiated – maintains functionality of original tissue
     • Paraneoplastic – nonendocrine
     • 2. Closely resembles original tissue
     • 3. DEC rate of mitosis
   • Malignant
     • 1. Anaplastic, undifferentiated cells
     • ^ Growth + anaplasia = malignancy
     • 2. Dysplasia – epithelial, ^ mitoses
     • >> carcinoma in situ

4. Charactaristics

   • Cells
     • Growth
       • Spread
         • Effects
           • Rare systemic effects, life-threatening only in brain
           • Systemic effects
           • Tissue destruction and spread can be life-threatening
         • Remains localised
         • Invades surrounding tissue
         • Metastases through lymph and blood
       • Slow expanding mass
       • Encapsulated
       • Rapid, infiltrating
       • No capsule
     • Well differentiated
     • Similar to normal cells
     • Relatively normal mitosis
     • Many undifferentiated
     • Varied size, shape, nuclei
     • ^ and atypical mitosis

5. 2. Rate of growth

   • Benign usually slower
   • Malignant > faster > invade local tx > mestases > death

6. 3. Local invasion

7. 4. Metastases

   • 3 pathways
     • Seeding within body cavities
     • Lymphatic spread
     • Haematogenous spread