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New advances in diagnostic procedures I. IMMUNOHISTOCHEMISTRY: Immunohistochemistry or IHC refers to the process of detecting antigens (e.g., proteins) in cells of a tissue section by exploiting the principle of antibodies binding specifically to antigens in biological tissues. IHC takes its name from the roots "immuno," in reference to antibodies used in the procedure, and "histo," meaning tissue (compare to immunocytochemistry) This involves the detection of cell products or surface markers by monoclonal antibodies. The binding of antibodies can be detected by fluorescent labels or chemical reactions that result in the generation of a colored product. This technique is useful in: 1. Categorization of undifferentiated malignant tumors e.g., cytokeratin in carcinoma and desmin in tumors of muscle. 2. Classification and categorization of leukaemias and lymphomas; B and T cell lymphomas can be identified. 3. Determination of the site of origin of metastasis using antibodies against tissue specific antigens. e.g., thyroglobulin and PSA (prostatic specific antigen) in thyroid and prostatic neoplasms respectively. 4. Detection of molecules that have therapeutic or prognostic significance e.g., estrogen and progestrone receptors in breast cancer. Products of certain cancer suppressor genes (e.g., p53) and oncogenes (e.g., c-erb B2) can also be detected. Over-expression of the latter in breast cancer is associated with poor prognosis. Immunohistochemical stain of estrogen receptors in CA breast II. FLOW CYTOMETRY Flow cytometry is a technology that is used to analyse the physical and chemical characteristics of particles in a fluid as it passes through at least one laser, cell component are fluorescently labelled and then excited by the laser to emit light at varying wavelength, the main application in tumor are: 1- measure the DNA content of tumor cells. Aneuploidy correlate with poor prognosis in early stage breast cancer, colorectal, prostatic, urinary bladder and lung cancers. 2- Identification of cell surface antigens by flow cytometry is widely used in the classification of leukemias and lymphomas. III-Cytogenetics: This study include karyotype analysis and abnormal genetics alteration in specific tumors example of this application are: 1-polymerase chain reaction (PCR) 2-FISH (filter in situ hybridization ) FISH (filter in situ hybridization ) This new teq. Used for detection of specific DNA or RNA in tissue sections or cell preprations by used of labelled complementary nucleic acid sequence or probe . This applied for detection of viral sequnce in cells infected by HPV,EBV, or HIV viruses or any genetics abnormality occur in special types of tumors. Breast cancer cells, HER2/neu amplified vs. HER2/neu nonamplified - High power These images show fluorescence in situ hybridization (FISH) of DNA probes to interphase chromosomes. DNA probes specific for the HER2 gene (red) and a control gene (green) were used on sections taken from the patient's tumor (left panel) and from a different patient's breast cancer (right panel). HER2 gene amplification is evident in the patient sample on the left. IV. TUMOR MARKERS: These are tumor derived or associated antigens, enzymes, cytoplasmic proteins and hormones that can be detected in blood or other body fluids. They are not primary methods of diagnosis but are useful adjuncts. They are also of value in monitoring therapy and in early detection of relapse. Two widely used markers are: 1. Carcinoembryonic antigen. This is normally produced by fetal gut, liver, and pancreas. It may be elaborated by cancers of the colon, pancreas, stomach, lung and breast. Less consistent elevations may be seen in some non-neoplastic conditions e.g., alcoholic hepatitis, cirrhosis and ulcerative colitis. This antigen is of value in detecting tumor burden in colorectal cancer and in detecting recurrences after surgery. 2. Alpha-fetoprotein, which is normally produced by fetal yolk sac and liver. Markedly elevated levels are seen in hepatic carcinomas and nonseminomatous testicular germ cell tumors. Less marked elevations may be seen in hepatitis and cirrhosis. It is useful as an auxiliary diagnostic aid of liver or testicular tumors, in monitoring therapy and assessing recurrence. TUMOR MARKER HORMONES Human chorionic gonadotropin Calcitonin Catcholamines and metabolites Ectopic hormones ONCOFETAL ANTIGENS Alpha-fetoprotein Carcinoembryonic antigen ASSCIATED CANCERS Trophoblastic and nonseminomatous germ cell tumors. Medullary carcinoma of the thyroid. Pheochromocytoma and related tumors. Small cell carcinoma and squamous cell carcinoma of the lung, etc Hepatocellular carcinoma and Nonseminomatous germ cell tumors. Carcinomas of the colon, pancreas, stomach, lung and breast. ISOENZYMES Prostatic acid phosphatase Neurone specific enolase. Prostatic cancer. neuroblastomas, small cell carcinoma-lung. SPECIFIC PROTEINS Immunoglobulins PSA Multiple myeloma, NHL Prostatic cancer. MUCINS AND GLYCOPROTEINS CA-125 CA-19-9 CA-15-3 Ovarian cancer Colonic and pancreatic cancer Breast cancer End