M5 (neoplasm) lect

• Neoplasia


  The condition of having neoplasm
• Neoplasm


  An abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of the normal tissues and persists in the same excessive manner after cessation of the stimuli which evoked the change
• One of the characteristics of Cancer is their unlimited replicative potential
• The formation of Neoplasia is often due to genetic changes, autonomous growth, and clonal production of abnormal cells
• mesenchymal tumors (mesodermal derived)

  chrondroma: cartilaginous tumor

  fibroma: fibrous tumor

  osteoma: bone tumor
• epithelial tumor (ecto-or endo-derived)

  adenoma: tumor forming glands - looks like a gland on microscope

  papilloma: tumor with finger like projections

  papillary cystadenoma: papillary and cystic tumor forming glands
• polyp

  • a "tumor " that projects above a

  mucosal surface

  • they can be found on the digestive tract, excretory system and genitourinary tract
• Colonic polyps - also called adenomas, sometimes called tubular adenomas, adenomatous polyp, sometimes "villous" adenoma.
• Sarcomas: mesenchymal tumor

  • chrondrosarcoma: cartilaginous tumor
  • fibrosarcoma: fibrous tumor
  • osteosarcoma: bone tumor
• carcinomas: epithelial tumors

  • adenocarcinoma: gland forming tumor
  • squamous cell carcinoma: squamous differentiation
  • undifferentiated carcinoma: no differentiation
• carcinomas can arise from ectoderm, endoderm, or less likely, mesoderm
• Mixed tumors: e.g. pleomorphic adenoma of salivary gland
• These are tumors whose components arise from various germ layers or cells

  mixed tumors
• Teratoma - Tumor comprised of cells from more than one germ

  layer, Have an abnormal mass of tissue whose cells

  originate from different germ layer
• teratoma arise from totipotent cells (usually gonads)
• benign cystic teratoma of ovary is the most common teratoma
• Hamartoma - disorganized mass of tissue whose cell types are indigenous to the site of the lesion, e.g., lung
• Choriostoma - ectopic focus of normal tissue (heterotopia), e.g., pancreas, perhaps endometriosis too

  Note: These are not harmful or cancerous
• aberrant differentiation (not true neoplasms)

  • Hamartoma
  • choriostoma
• misnomers

  • hepatoma
  • melanoma
  • seminoma
  • lymphoma
• Hepatoma: Malignant Liver Tumor

  o Hepatocellular Carcinoma
• Melanoma: Malignant Skin Tumor

  o Basal Cell Carcinoma

  o Squamous Cell Carcinoma
• Seminoma: Malignant Testicular Tumor

  o Testicular Cancer
• Lymphoma: Malignant Tumor of Lymphocytes

  o Non Hodgkin Lymphoma (NHL)

  o Hodgkin Lymphoma
• Malignant change in the target cell, referred to as transformation
• Well differentiated neoplasm - resembles mature cells of tissue of origin, this is benign.
• poorly differentiated neoplasm - composed of primitive cells with little differentiation
• Undifferentiated or "anaplastic" tumor

  o Correlation with biologic behavior
• Pleomorphism (Variability of Cancer Cell to the)

  • Size
  • Shape (Irregular shape)
• hyperchromasia - it means increase staining characteristics of the chromatin
• Leiomyoma of the uterus - this benign, well differentiated tumor contains interlacing bundles of neoplastic smooth muscle cells that are virtually identical in appearance to normal smooth muscle cells in the myometrium.

  
• dysplasia - abnormal growth
• Rate at which tumor cells are shed or lost

  • apoptosis
  • maturation
• G0 - is the dormant stage of the cell, it means they

  remain inactive for cell division
• Transformed cells can die due to apoptosis or natural maturation process
• Nonproliferative pool - is the collection of cells that

  cannot undergo cell division
• Proliferative pool - is the collection of cells that can

  undergo cell division
• features of malignant tumors

  • cellular features
  • local invasion (can invade an organ locally)
  • metastasis (spread to other organs or location)
  • unequivocal sign of malignancy
  • seeding of body cavities
  • lymphatic (will spread to the lymphatic vessels)
  • hematogenous (in the blood stream)
• BENIGN VS MALIGNANT

  
• Geographic and environments

  • sun exposure
  • smoking and alcohol abuse
  • body mass
  • environmental vs. racial factors
  • viral exposure