10a - Neoplasia.pdf

Neoplasia Text Book Chapter 6  Nomenclature  Epidemiology  Classification  Metastasis  Molecular Genetics  Epigenetic Changes  Carcinogenic Agents  Clinical Aspects  Diagnosis Introduction...

Neoplasia Text Book Chapter 6  Nomenclature  Epidemiology  Classification  Metastasis  Molecular Genetics  Epigenetic Changes  Carcinogenic Agents  Clinical Aspects  Diagnosis Introduction to Neoplasia  Neoplasia: literally means “the production of new growth” o Neoplasia produces a neoplasm  Neoplasm = an abnormal mass of tissue, the growth of which exceeds and is uncoordinated with the tissue around it and continues even when the stress that produced it is removed.  Tumor: originally just meant a swelling, but now reserved for swellings that are caused by neoplasia  Oncology- the study of and the treatment of tumors  Benign tumors o Tumors that stay localized, will not spread to other sites, and is amenable to local surgical removal, and very rarely cause death o benign tumors are designated by attaching the suffix -oma to the name of the cell type from which the tumor originates o fibroma, chondroma, ademoma, papilloma, lipoma, osteoma, myoma (leiomyoma, rhabdomyome), angioma  Malignant tumors o Tumors that are progresivaly invading and infiltrating surrounding tissue, are capable of metastasizing and can cause death o ultimately caused by inherited or spontaneous genetic alterations (i.e. mutations or epigenetic modifications) in the expression or function of key genes that regulate fundamental cellular processes, such as growth, survival, and senescence.  sarcomas (Greek sar = fleshy) in solid mesenchymal tissues: fibrosarcoma, chondrosarcoma, leiomyosarcoma, and rhabdomyosarcoma,  from blood-forming cells: leukemias (literally, white blood) or lymphomas (tumors of lymphocytes or their precursors).  of epithelial cell origin carcinomas.  Characteristics that differentiate Benign and Malignant Tumors Dr M Hossu Notes 144   Tissue differentiation  Rate of growth  Local effects  Distant spread Epidemiology  Distribution and patterns of disease conditions  Incidence  Mortality Geographic and environmental influences  Sun exposure & skin cancer cancer: white population in Australia,, Northern Europe, Europe US, Canada  EBV & Malaria: Burkitts lymphoma  Hepatocellular carcinoma carcinoma: HepB virus versus other factors (aflatoxin – from soil, on crops and seeds) Age related differences  young children (under the age of 5): acute leukemias and the malignancies of the primordial cells.  children age 5- 9: leukemias, neuroblastomas and retinoblastomas, hepatomas, soft tissue sarcomas and osteogenic sarcoma  children age 9-14: hepatosarcomas, osteogenic sarcomas, thyroid carcinoma and Hodgkin’s lymphoma  Young adults: Hodgkin’s lymphoma, acute myeloid leukemia, seminoma of the testis  Middle aged adults: appearance of the carcinomas, chronic myeloid leukemia and lymphomas  Older adults: carcinomas, chronic lymphocytic leukemia, lymphoma, osteogenic sarcoma Inherited predisposition to cancer  Familial cancers  Autosomal recessive syndrome o of defective DNA repair  Pre-neoplastic disorders  Gastric atrophy → gastric carcinoma  Actinic dermatitis of the skin → squamous carcinoma of the skin  Barrett’s esophagus → adenocarcinoma of the esophagus  Cirrhosis of the liver → hepatocellular carcinoma  Paget’s disease of bone → osteosarcoma  Immunodeficiency states and autoimmune diseases → lymphomas  Dysplasias of epitheliums are precursors to carcinomas Dr M Hossu Notes 145