Carcinomas, connective tissue

Malignant cells are divided into categories based on the cells of origin. Carcinomas arise from epithelial cells, whereas sarcomas arise from muscle or connective tissue. Adenocarcinomas arise from glandular tissue. Carcinoma in situ refers to cells limited to epithelial origin that have not yet invaded the basement membrane. 

Cancer is a disease characterised by uncontrolled proliferation of cells that produces a tumour, from which the cells can invade local tissues and then spread to give rise to metastases. Cancers are classified into three groups carcinomas, sarcomas and leukaemias/lymphomas. Carcinomas, the most common, arise in epithelial cells, sarcomas in connective tissue (e.g. bone, cartilage) and leukaemias and lymphomas from white blood cells. 

Mitotic effect. STE, administered to the buccal mucosa of 15 female HMT rats, 6 months of age, weekly for 1 year, produced hyperorthokeratosis, acanthosis, numerous binucleate spinous cells, and subepithelial connective tissue hyalinization. Verrucous carcinoma and squamous cell carcinoma were not seen. Karyotyping revealed that lymphocytes of tobacco-treated, as well as control rats, had normal chromosome number and morphology. However, approx 25% of buccal epithelial cells of the tobacco-treated rats were tetraploid and 5% octa-ploid, compared with only 11% tetraploid and no octaploid in the controls. Results indicated that the mitotic process could be disturbed by tobacco treatment b Molluscicidal activity. Water extract of the dried leaf, at a concentration of 168 ppm, produced equivocal effect on Lymnaea luteola . 

Fig. 15. The antiblastic effect of 1-ethoxysilatrane a) tumorous tissue of Walker carcinoma (control) b) lymphocytes,fibroblasts and collagen blocks c) larger collagen blocks d) connective tissue capsula surrounding tumor cells...

Another advantage of immunohistochemistry is that tissues of a small size (e.g., biopsies) can be used. This is important because it is better to detect tumors at an early stage, when they are small. The necessity of early detection cannot be overemphasized. Very small tumors and fine-needle aspirates cannot be used for biochemical assays. Although the DCC assay provides quantitative results, it does not take into account the relative amount of the connective tissue in the specimen, the presence of carcinoma in situ lesions, or normal ducts and lobules. These limitations are not encountered when using paraffin sections. In addition, immunohistochemistry allows the use of archival tissues when fresh tissues are not available. This method does not require any special, expensive equipment and can be carried out in any standard laboratory. 

Cancer is uncommon during the first two decades of life, but is nonetheless a substantial concern. In the United States, cancer is diagnosed in approximately 12 400 children and adolescents annually and is the most common cause of death from any kind of disease between 1 and 19 years of age. In the United States and other developed countries, lymphoid neoplasms (leukaemia, lymphoma) and cancers of the central nervous system are the most common paediatric malignancies. Other kinds of childhood tumours include embryonal tumours of the retina, sympathetic nervous system, kidney, and liver tumours of bone and soft connective tissues and certain gonadal neoplasms. Different kinds of cancer (e.g. carcinomas of liver or thyroid) may predominate in children in parts of the world where specific environmental risk factors are more prevalent. 

In connective tissue diseases, particularly skin carcinoma and degenera-... 

In Vitro. Mouse connective tissue (L cells), human cervical carcinoma (HeLa), and human amnion (WISH) cancer cells were used to determine the toxic and nontoxic levels of several of the... 

Primary IgA nephropathy an immune-complex-mediated disease in which IgA deposits and other pathologic lesions are found in kidney tissues. In contrast, Henoch-Schonlein purpura is a systemic disease that is believed to be closely linked to IgA nephropathy because they share similar immunohistologic features. Only the joints, skin, and gastrointestinal tract are affected in Henoch-Schonlein purpura. Mesangial deposition of IgA immune complex is also seen in patients with celiac disease and dermatitis herpetiformis, possibly due to an increased exposure to antigens. Patients with chronic liver disease may have IgA nephropathy because of reduced clearance of IgA immune complexes. Secondary IgA nephropathy may be present in patients with different connective tissue diseases, carcinomas, and HIV infection. 

Cancers are classified by the tissues affected. The vast majority of cancerous tumors are carcinomas (tumors derived from epithelial tissue cells such as skin, various glands, breasts, and most internal organs). In the leukemias, cancers of the bone marrow, excessive leukocytes are produced. Similarly, the lymphocytes produced in the lymph nodes and spleen proliferate uncontrollably in the lymphomas. Tumors arising in connective tissue are called sarcomas. Despite the differences among this diverse class of diseases, they also have several common characteristics, among which are the following ... 

Normal animal cells are often classified according to their embryonic tissue of origin, and the naming of tumors has followed suit. Malignant tumors are classified as carcinomas if they derive from endoderm (gut epithelium) or ectoderm (skin and neural eplthella) and sarcomas if they derive from mesoderm (muscle, blood, and connective tissue precursors). The leukemias, a class of sarcomas, grow as individual cells in the blood, whereas most other tumors are solid masses. (The name leukemia is derived from the Latin for white blood the massive proliferation of leukemic cells can cause a patient s blood to appear milky.)... 

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