Neoplasia Lecture Notes PDF

Neoplasia Dr. Hasnaa Saleh 1  Intended Learning Outcomes After this lecture, the student will be able to: Explain the concept of Neoplasia. Differentiate between the Two types of Neoplasia. Identify the different causes of tumors....

Neoplasia Dr. Hasnaa Saleh 1  Intended Learning Outcomes After this lecture, the student will be able to: Explain the concept of Neoplasia. Differentiate between the Two types of Neoplasia. Identify the different causes of tumors. Illustrate clinical manifestations of cancer. Mention the Stages of cancer spread. Describe the diagnosis of cancer. Define the treatment of cancer.  Cell Proliferation Cells normally differentiate, grow, mature, and divide. These are regulated processes, balanced in a healthy system. Cell proliferation is the process by which cells divide and reproduce. Cell division provides the body with the means for replacing cells that have a limited life span such as skin and blood cells, increasing tissue mass during periods of growth, and providing for tissue repair and wound healing. 3  Cell Differentiation Cell differentiation is the process whereby proliferating cells are transformed into different and more specialized cell types. This process leads to a fully differentiated, adult cell that has achieved its specific set of structural, functional, and life expectancy characteristics. For example, a red blood cell is programmed to develop into a concave disk that functions as a vehicle for oxygen transport and lives approximately 120 days 4  Neoplasm The TUMOR is a self-controlling new growth (autonomous) formed by unlimited multiplication of abnormal cells in one of the body tissues or organs forming a mass. The term NEOPLASM refers to an abnormal mass of tissue in which the growth exceeds and is uncoordinated with that of the normal tissues. Unlike normal cellular adaptive processes such as hypertrophy and hyperplasia, neoplasms do not obey the laws of normal cell growth.  Two major types of Neoplasm: Neoplasms usually are classified as benign or malignant. Benign Neoplasms: Neoplasms that contain well-differentiated cells that are clustered together in a single mass. It is a well-differentiated tumors that resemble the tissues of origin but have lost the ability to control cell proliferation. They grow by expansion, are enclosed in a fibrous capsule, and do not cause death unless their location is such that it interrupts vital body functions. Malignant Neoplasms are less well-differentiated tumors that have lost the ability to control both cell proliferation and differentiation. They grow in a crablike manner to invade surrounding tissues, have cells that break loose and travel to distant sites to form metastases, and inevitably cause suffering and death unless their growth can be controlled through treatment. malignant neoplasms are less well differentiated and have the ability to break loose, enter the circulatory or lymphatic systems, and form secondary malignant tumors at other sites. 8  CAUSES OF CANCER ❑ Heredity A hereditary predisposition has been observed in approximately 50 types of cancer. For example, breast cancer occurs more frequently in women whose grandmothers, mothers, aunts, and sisters also have experienced a breast malignancy. ❑ Carcinogenic Agents Chemical Carcinogens: smoking, dietary factors, and alcohol consumption. Radiation Oncogenesis: Prolonged exposure to ultraviolet rays (sun ) can cause skin malignancy. Ionizing radiation causes leukemia, osteosarcoma, skin malignancy, and lung cancer. ❑ Oncogenic Viruses: hepatitis B & C (liver cancer), or RNA viruses as in human T cell Leukemia virus-1, Herpes simplex type 2 also has been associated with cervical cancer. ❑ Immunologic Defects: impaired immune system 9  Clinical Features of cancer Bleeding and hemorrhage Ulceration, and infection of the tumor area Effusion in serous cavities Increased risk of vascular thrombosis Anemia Bone destruction Hypercalcemia Pain Cachexia, weakness, and wasting of tissues.  Diagnosis Screening procedures include: x-ray studies. endoscopic examinations. urine and stool tests. blood tests for tumor markers. Tissue biopsy. bone marrow aspirations. ultrasound imaging (US) magnetic resonance imaging (MRI). computed tomography (CT) scan. T stands for the extent of the primary tumor. N refers to the involvement of the regional lymph nodes. M describes the extent of the metastatic involvement. The time of staging is indicated as: cTNM, clinical-diagnostic staging. pTNM, postsurgical resection-pathologic staging. sTNM, surgical-evaluative staging. rTNM, retreatment staging. aTNM, autopsy staging  Treatment oChemotherapy oRadiation oImmunotherapy oSurgery 13  Side effects of treatment Gastrointestinal tract: Oral ulcers, malabsorption, diarrhea, and vomiting. Bone marrow: Chemo Rx and radiotherapy suppress bone marrow: decrease in red blood cells, white blood cells, and platelets. Hair and skin: alopecia and skin dryness. Reproductive tract: affects gametes, premature menopause. Thanks