Neoplasia Lecture Notes PDF

Neoplasia Neo- -plasia New Growth  Neoplasia A growth of new cells that proliferates without control, serves no useful function, and has no orderly arrangement.  Oncology is the study of neoplasia, and this word is the basis of oncoge...

Neoplasia Neo- -plasia New Growth  Neoplasia A growth of new cells that proliferates without control, serves no useful function, and has no orderly arrangement.  Oncology is the study of neoplasia, and this word is the basis of oncogenesis and oncogenic, which relate to the induction of neoplasia. The common term for a neoplasm is cancer or tumor. Characters of neoplasm: 1. Its growth rate exceeds the normal rate of growth and uncontrolled. 2. The cells of malignant neoplasm not similar to the normal cells of the affected tissue. 3. Neoplasms without any useful functions, but may produce toxins. 4. Neoplasms have no normal arrangement. 5. Without unclear understood causes.  The differences between neoplasia and hyperplasia Neoplasia Hyperplasia Cause -Unknown -Known Rate of growth -Rapid and not depend upon the -Slow and depend upon stimulus and not stopped after the cause and stopped remove the stimulus. after remove the cause. Morphology of -Undifferentiated and not similar to -Similar to the original the cells original cells. cells. Tissue affected -Multiple -Single Mitotic division -Both typical and atypical mitotic -Absent division are present. Metastatis -Occur -Not occur  Chemical carcinogens Radiation Viruses Characteristic of Neoplasm 1- Behavior  Classification of neoplasms -According to the naked eye appearance the neoplasms may be scirrhous, encepholoid, cystic or soft. -According to the embryological classification neoplasms may be said to ectoderm, endoderm of mesoderm. Such tumors of the embryonal origin are known as teratomas. -According to the etiological classification is unsatisfactory because no definite causes of neoplasms where known. -According to the histological classification the neoplastic cells are differentiated (similar to the cells of the originated cells) or undifferentiated (similar to the embryonal cells.). -According to the histogenic classification the neoplasms may be epithelial tissue tumors of non epithelial tissue tumors (mesenchymal). -According to the behaviour classification, the neoplasms may be benign or malignant.  1- Effect on the host Harmless Harmful Unless interferes with function of important organs 2- Rate of growth Slow Rapid  3- Mode of growth Expansion Infiltration, invasion, destruction and penetration  4- Localization Localized Not localized  5- Metastasis No metastasi Metastasized s  Metastasis Spread of malignant cells from one part of the body to another through the blood vessels or.lymphatic as an embolus Malignant tumors spread by: 1-Hematogenous spread 2- Lymphatic spread Transcoelomic -3 spread 4- Implantation  1-Hematogenous spread The favored pathway of sarcoma, but is also utilized by some carcinoma The most common places for the metastases are Liver Lung Bone  3- Transcoelomic spread This spread through the serous cavities. It occurred in tumors of organs covered by serous membranes. 3- Transcoelomic spread  4- Implantation Implantation through Direct implantation natural passages detached malignant During cells from surgical removal carcinoma of the of malignant tumor, renal pelvis malignant cells may Get implanted on the get implanted in mucosa of the the surgical urinary bladder forming metastatic wound forming nodules. metastatic nodules.  6- Removal Easily Difficult  7- Recurrence No recur recurrenc e  8- toxicity Not toxic Toxic  Malignant tumors Benign tumors Behavior Harmful -Harmless 1-Effect on the host Rapid Slow 2- Rate of growth progressive infiltration, 3- Mode of growth invasion, destruction Expansion not localized Localized 4- Localization: Metastasized no metastasis 5- Metastasis Difficult not difficult 6- Removal recur after apparent no recurrence after removal removal 7- Recurrence Toxic Not toxic 8- Toxicity Characteristics of Neoplasm  Incidence Single Single or multiple  Shape On body surfaces: Wart like  Shape On body surfaces: Fungating Ulcerative or infiltrating  Shape In solid tissue In solid tissue: Rounded or Irregular elliptical  Encapsulation Present Absent Area of degeneration and necrosis Absent Present Malignant tumors Benign tumors Gross appearance - Single or multiple - Single -Occurrence: - Shape: -irregular - Round or elliptical In solid tissue: Polypoid (fungating, -wart like or On body surface: ulcerative or infiltrating. pedunculated. Absent - Present Encapsulation: -Present - Absent Area of degeneration and necrosis The morphology of tumor cells Normal in Abnormal in relation to relation to adjacent tissue. adjacent tissue  Differentiation Differentiated Loss of differentiation  Anaplasia no or Marked minimal evidence evidence of anaplasia. of Anaplasia The reversion of cells to the emberyonal type.  I- Cellular changes: 1- Pleomorphism : the cells show variation in size and shape. 2- The cells are larger than normal cells Rhabdoid renal cell carcinoma  II- Nuclear changes: 1- Hyperchromasia: the nuclei are enlarged and deeply stained due to duplication of DNA before mitotic division. 2- The nucleocytoplasmic ratio is increased. 3- Nuclear pleomorphism: The nuclei are variable in size, shape and position within the cells.  II- Nuclear changes: 4- The nucleolus is frequently present and often large. 5- Mitotic figures: The nuclei show many mitosis which may be abnormal in shape and variable in size and pattern.  Hyperchromasia N/C ratio is increased Nuclear pleomorphism Prominent nucleoli Parent cell Prophase Metaphase Anaphase Telophase Mitotic figures Mitotic figure - Presence of tumor giant cells; due to repeated division of the nucleus in rapidly growing tumors without division of the cytoplasm. Tumor giant cell Changes in cellular pattern: Malignant tumors show loss of polarity i.e. loss of relation between each cell and the neighboring ones and surrounding tissue.  Extension and infilteration It doesn’t extend It extend beyond the beyond the basement membrane basement membrane or the basal layer of or the basal layer of the cells. the cells. The tumor doesn’t The tumor infiltrate infiltrate or through any penetrate the connective tissue connective tissue capsule capsule. Malignant neoplasm extended through basement membrane  Invasion of blood vessels There is no Invade blood vessels invasion of blood and lymphatics vessels or lymphatics.  Invasion of blood vessels Degenerative and necrotic changes Absent Present Malignant tumors Benign tumors Microscopical appearance -loss of differentiation -Differentiated 1-Differentiation Present Absent 2- Feature of anaplasia: Lack of maturity Mature 3- maturity of cells Present Few or absent 4- Mitotic figure Present and may be Absent 4- Invasion of blood abundant supply Present Absent 5- Degenerative and necrotic changes