Neoplasia

• Neoplasia


  Abnormal growth of new cells that may develop into a tumour
• Neoplasia

  • Neoplasia is a process
  • Neoplasia consists of stepwise abnormal changes in cellular structure and function
  • These cellular changes carry abnormal proliferative, invasive, and metastatic potential (the hallmarks of cancer)
• Abnormality in cell proliferation


  Pathophysiology of neoplasia
• Loss of tumor suppressor genes

  Cell responses to stimuli
• Changes in cell size

  • Hypertrophy (increase in cell size in response to a stimulus)
  • Hyperplasia (increase in cell number in response to a stimulus)
• Changes in cell size and number

  • Cell multiplication with disordered growth and maturation of cells, cells with changed appearance under the microscope
  • Dysplasia = Pre-cancer
  • Hyperplasia
  • Dysplasia
  • Metaplasia
• Metaplasia


  Change from one type of differentiated tissue to another
• Neoplasm


  • New growth
  • Tumor
  • Cancer
• Oncology


  Study of tumors
• What causes the development of tumours

  Uncontrolled cell growth leads to tumour formation
• Benign neoplasm


  • Does not spread
  • Grows without spreading
  • Has well demarcated borders
  • Growth can be slow or very slow
  • Does not metastasize
  • Often but not always these lesions are NOT life threatening (exceptions)
  • Often curable by surgical excision
  • Similar cell arrangement to parent tissue
  • Similar cell type to parent tissue (cell differentiation)
  • Evidence of normal cell function
  • Either infrequent or absent mitotic figures
• Malignant neoplasm


  • Signs of local spread (infiltration)
  • Signs of rapid growth rate (numerous mitosis)
  • Anaplasia (lack of cellular differentiation, high ratio of nucleus to cytoplasm, intense nuclear staining, clumped chromatin, prominent nucleoli)
  • Pleomorphism (variation in cell size and shape, presence of giant cells)
  • Change in the arrangement of cells
  • Local spread
  • Spread to distant locations = metastasis
  • Often fatal if untreated
  • Cells infiltrate other tissues
  • Grow rapidly
  • Haphazard cell arrangement
  • Less cellular resemblance to parent tissue
  • Cells vary widely in size, shape and nuclear configuration
  • Less evidence of normal function
  • Frequent mitoses of abnormal type
• Proliferating (neoplastic) cells + (Non-neoplastic) supportive connective tissue + Blood vessels = Neoplasm
• Supportive connective tissue = Stroma
• Neoplasm name


  Derived from the neoplastic component + modifier (benign or malignant) + site of origin
• Benign neoplasm naming


  Often designated by adding the suffix "oma" to the prefix which designates the cell of origin
• Benign epithelial neoplasms


  • Adenoma - glandular epithelium
  • Cystadenoma - cystic or fluid filled cavity
  • Papilloma - producing finger-like projections
• Malignant epithelial neoplasms


  • Epidermoid Carcinoma (squamous epithelium)
  • Adenocarcinoma (glandular epithelium)
• Malignant connective tissue neoplasms

  • Chondrosarcoma - malignancy of cartilage
  • Liposarcoma - malignancy of fat tissue)
  • Rhabdomyosarcoma - malignancy of skeletal muscle
  • Leiomyosarcoma - malignancy of smooth muscle cells
  • Osteosarcoma - malignancy of bone cells
• Other neoplasm types (teratomas)


  • Germ cells
• How neoplasms spread


  • Local invasion
  • Lymphatic dissemination (lymph nodes)
  • Blood (haematogenous) dissemination (lung, liver, bone, brain)
  • Implantation in body cavities (transcoelomic) (pleural, peritoneal)
  • Perineural
  • Intra-epithelial
• Benign Neoplasms

  • Lipoma = fat tissue
  • Chondroma = cartilage
  • Osteoma = bone
  • Hemangioma = blood vessel
  • Fibroma = fibrous tissue
• Cancer Staging

  How large the cancer/neoplasm is and whether it has spread
• Cancer Grading


  How abnormal the cancer cells look under a microscope
• Staging Systems


  • Neoplasm location
  • Cell type (ex.: adenocarcinoma, liposarcoma)
  • Neoplasm size
  • Spread to nearby lymph nodes
  • Spread to a different part of the body
  • Tumour Grade (how abnormal the neoplastic cells look)
• TNM Staging System


  Tumour - size and extent of the primary tumor

  Nodes - number of nearby lymph nodes involved

  Metastatis - has it metastasized
• The TNM staging system stands for Tumour, Node, Metastasis
• The system uses letters and numbers to describe the cancer
• TNM Staging


  • T2 N1 M0 - small cancer that has spread to the lymph nodes but not elsewhere
  • T4 N3 M1 - more advanced cancer that has spread
• Primary tumor (T)


  • TX: Main tumor cannot be measured
  • T0: Main tumor cannot be found
  • T1, T2, T3, T4: Refers to the size and/or extent of the main tumor. The higher the number after the T, the larger the tumor or the more it has grown into nearby tissues. T's may be further divided to provide more detail, such as T3a and T3b.
• Regional lymph nodes (N)

  • NX: Cancer in nearby lymph nodes cannot be measured
  • N0: There is no cancer in nearby lymph nodes
  • N1, N2, N3: Refers to the number and location of lymph nodes that contain cancer. The higher the number after the N, the more lymph nodes that contain cancer.
• Distant metastasis (M)


  • MX: Metastasis cannot be measured
  • M0: Cancer has not spread to other parts of the body
  • M1: Cancer has spread to other parts of the body
• Local Effects of Cancer

  • Compression - if compresses a hollow organ like the oesophagus could cause an obstruction.
  • Obstruction
  • Infiltration
  • Erosion
  • Ulceration
  • Perforation
  • Rupture
  • Bleeding
  • Infarction
  • Osteolysis
  • Pathological fractures
  • Deformities
  • Pain
  • Cell death
  • Interference with structure and function of neighbouring tissues, organs and systems
• Systemic Effects of Cancer

  • Metabolic effects
  • Tissue waste
  • Weight loss
  • Anaemia
  • Immunosuppression
  • Bleeding
  • Endocrine effects
  • Paraneoplastic syndromes
• Paraneoplastic syndromes


  Complications of cancer that cannot be attributed to direct effects of the neoplasm or its metastases
• 1950s Male/Female ratio 6:1, this is now 7:5 (decreasing male smoking rates, increasing female smoking rates)
• Approximately 23,000 men and 15,000 women diagnosed with lung cancer per year
• Lung cancer is the 2nd most common cancer in men (after prostate) and 3rd in women (after breast and bowel)
• Smoking


  Over 80% (Association for international Cancer Research) or 9 out of 10 (Cancer Research UK) lung cancers are caused by smoking (passive included)
• Other lung cancer risk factors

  • Exposure to industrial carcinogens and air pollution
  • Scarring from previous lung disease
  • Family history
  • Past cancer treatment