Abnormal cell growth can be a precursor for tumors either benign or malignant. The type of tumors have slightly different traits which helps distinguish them. Presence of the tumor can exhibit general symptoms of disease. The immune system can also fight normal tissue cells, which are mistakened as pathogens.
DISORDERS OF GROWTH
Normal cell growth is vital for optimum function of the cell, tissue or organ. The normal growth can avoid processes such as atrophy ( decrease in size), hyperplasia and hypertrophy (increase in size), metaplasia( replacement of one cell type with another), neoplasia ( growth of tumor) and anaplasia( no differentiating) of the cell. These processes are a result of cellular adaptation of growth to preserve the cells fuction. In my first blog I mentioned cell injury.If the injury is non-fatal it can lead to adaptation of the cell by conforming into one of the processes. The processes can either be physiological or pathological.
figure 1.1 A diagram indicating the
events during pathological and physiological
hypertrophy of the heart.
figure 1.2 . An image showing muscular autrophy
figure 1.3 . Endometrium hyperplasia due to overgrowth of endometrium
figure 1.4. transitional- squamous metaplasia
CLASSIFICATION OF TUMORS
There was a time when I thought the word ” TUMOR” only referred to cancerous cell growth. Not knowing that a tumor can either be benign or malignant. In my understanding a tumor is the abnormal overgrowth of cells .A malignant tumor can become metastatic resulting in a lethal effect to the bodies physiology. Where as a benign tumor cannot and usually has a good prognosis. ” Tumors are classified according to the tissue of origin, epithelial, connective tissue, haemopoietic, neural and a miscellaneous group and then into benign and malignant within these groups”. 1. JJ Rippey (1994). This is the extent of resemblance they depict of the tissue they originated from, which can be well or poor differentiation. The differentiation is often a sign of how serious the outcome of the tumor can be.
figure 2.1 growth of malignant and benign tumors
THE CHARACTERISTICS OF MALIGNANCY
I recall feeling a lump in my breasts for the first time in my early years of high school, my first thought was its ” cancer”, only to find out it was a breast fibroadenoma. Had it been a malignant tumor the lump would have had a different feel. ‘ malignant tumors grow by local invasion and infiltration with destruction of surrounding tissue.” JJ Rippey (1994). A malignant tumor has a hard irregular shape which is not easily eradicated. ” Tumors often lose differentiation features over time as they become more malignant.” 2.BF Burns. The differentiation often aids diagnosis and coming up with the appropriate therapy considering the extent and nature of the growth.
figure 3.1 a video about malignant and benign tumors
THE SPREAD OF MALIGNANT TISSUE
” Local spread takes place by invasion and infiltration between tissues.” JJ Rippey (1994). The cancer cells form an “army” removing/destroying original tissue and taking over the site by means of rapid proliferation. During invasion they leave the tumor site and continuously spread into neighboring tissue. Malignant tumors are best removed in their early stages due to to this phenomenon of metastasis, I often see the use of different therapies such as chemotherapy or surgical procedures in removing these tumors on TV. I now know why it is so vital to try and eradicate these tumors, considering their nature an the damage they can cause.
figure 4.1 the spread of a malignant tissue
Cancer is responsible for many deaths, which is can be caused by many factors. ” cancer is a complex group of diseases with many possible causes, including genetic factors and lifestyle factors.” 3. American cancer society. Age can also determine the chances of being diagnosed with cancer, which could be a build up of everyday damage to our cells and genes. Genetics and the enviroment are also contributing factors, such as long- term sun exposure, smoking or even viruses.
figure 5.1 . video showing formation of cancer
figure 5.2. a few causes of cancer
EFFECTS OF TUMORS
” Benign tumors can cause pressure and obstruction, functional activity, local anatomical complications and malignant complications. Malignant tumors can cause pressure and obstruction, destruction of tissue, ulceration, hemorrhage and secondary infection and pain.” JJ Rippey (1994). The effects caused by tumors are not different to signs and symptoms which manifest in other diseases. Some can appear to be non-fatal, which could cause misdiagnosis.
LOCALIZED AUTO-IMMUNE DISEASES
“An autoimmune disorder is a condition which occurs when the immune system mistakenly destroys healthy body tissue” 4. D Dugdale (2011). Psoriasis is an autoimmune disease which I am familiar with. The T-cells mistakenly identify the skin cells as foreign cells, resulting in the cells being attacked, the skin cells are harmed and damaged.
figure 6.1 Body parts that can be affected by autoimmune diseases
GENERALISED AUTOIMMUNE DISEASES
In the process of this group of diseases, the immune system problems affect collagen. ” Some of these diseases have similarities, including arthritis and inflammation of arteries in the tissues that connects joints and other tissues.”6. M.E Makover (2011).
figure 7.1 systemic sclerosis due to excessive collagen deposition
Cellular adaptation after injury can result in change in cells morphology, this is the cells way of fighting for survival. Tumors take on abnormal accumulation and over growth of cells and sometimes on abnormal structure. This reflects the possibilities of the tumor being malignant or benign. The immune system is there to fight off foreign substances in our bodies such as cancers. But in some cases the immune system can not differentiate whether a cell is normal or foreign, this is how autoimmune diseases come about.
1. JJ Rippey , General Pathology, 1994, Witswatersrand, pg 210, 215, 225, 289, 290.
2. Dr Bruce. F Burns, Anatomical Pathology, Neoplasia, Ottawa Hospital.
3. American society, What is cancer. http://www.google.co.za/url?q=http://www.cancer.org/cancer/cancercauses/&sa=U&ei=7X91UaqHE8LgOt7jgJgO&ved=0CB8QFjAA&sig2=pmoC5mxJ5G5irAXrxfsVdA&usg=AFQjCNFCuOs2Y-Hv_yEldQHqZuUhhCvwgg . 22 April 2013.
4. D.C Dugdale, Autoimmune disorders, 2011, University of Washington.http://www.nlm.nih.gov/medlineplus/ency/article/000816.htm. 22 April 2013.
5. M.E Mkover, Collagen Vascular Disease, 2011, New York University Medical centre. http://www.nlm.nih.gov/medlineplus/ency/article/001223.htm. 22 April 2013