10 - Overview of Neoplasia Flashcards
Define oncogene
Derived from mutations in protooncogenes and result in abberant growth and differentiation.
Define tumor supressor gene
Keep cell growth in check, suppressing abnormal cell growth and are thus good for the cell.
Define hyperplasia
Enlargement of an organ or tissue caused by an increase in reproductive rate of its cells. Increased number of cells.
Define dysplasia
Enlargement of an organ or tissue by the proliferation of cells of an abnormal type.
Define metaplasia
Change of one matured cell type to another cell type based on external stimuli; reversible process.
Define carcinoma in situ
Progression of malignant growth is as follows: hyperplasia, atypia, carcinoma in situ, primary cancer, metastasis. At this stage, there is abnormal growth of atypical cells, but they are in place. The standard is whether growth has broken through basement membrane.
Define invasive carcinoma
Abnormal cells have increased in motility and have been able to cross basement membrane into surrounding tissue. Have not spread to different organ yet.
Define metastatic carcinoma
Cancer that has metastisized has increased motility to the point where it has left the site of primary cancer, traveled through the lymphatic system, into vessels, and found a new home and continued growth.
Define hypertrophy
Increase in size of tisue or organ based on the increase in size of cells.
Define neoplasm/neoplasia
Abnormal mass of cells that grows at the expense of the host and is cause at least in part by genetic abnormalities of involved cells.
Define anaplasia
Loss of differentiation. This is a very worrisome sign in oncology. Cells that differentiate show that the normal pathway of development is at least partly intact. Anaplastic cells do not go through development and are frequently mitotic. Anaplastic tumors are always malignant.
Define adjuvant
Systemic treatment given after local measures were taken. For example, in breast CA, pt could have localized surgery, but still undergo systemic chemotherapy in order to kill any cells that were possibly missed and avoid the statistical relapse.
Define neoadjuvant
Therapy administered before the main treatment. It could be chemotherapy or hormone therapy given the type of tumor in order to atrophy the growth, thus making surgery a possibility or one that is more likely to succeed.
Define remission
Indicates that there is no measureable disease activity. However, it is not said to be cured as the return of CA is possible or even probable.
Define cure
100% removal of cancer cells. Nearly impossible to measure with current technology.
Differentiate between benign and malignant neoplasm according to architecture, rate of growth, pattern of enlargement, spread: Benign
Architecture: Well-differentiated, round nucleus, resembles progenitor.
Growth: Slowly over years.
Enlargement: Remain localized, expand slowly often compressing. Freely movable mass on palpation. Normal function, normal apoptosis.
Spread: Confined. May compress surrounding tissue but do not invade or metastisize.
Differentiate between benign and malignant neoplasm according to architecture, rate of growth, pattern of enlargement, spread: Malignant
Architecture: Range from well-defined to poorly differentiated. Nucleus and plasma membrane mis-shapen.
Growth: Variable and generally faster.
Enlargement: Invade surrounding tissue. Causes poorly demarcated, often “fixed” and immovable mass on palpation. Tissue invasion most reliable feature of malignancy. Abnormal apoptosis.
Spread: Can spread. The larger and more poorly differentiated the neoplasm the greater the chance of metastasis.
Identify the major pathways by which benign and malignant neoplasms spread throughout the body
Benign: Remain localized and inflict damage by encroachment on adjacent structures.
Malignant: Unrestrained growth with invasion of adjacent tissues; metastases to distant sites.
Pathways of spreading: Lymphatic invasion (malignant cells transported bia lymphatic vessels to lymph nodes and throughout body), blood borne transport (invasion of, usually, veins), seeding of body cavities, organs, and skeleton (direct penetration), angiogenesis (tumor blood vessel formation).
