Cytotech 1.docx

Cyto technology Is the study of human cells to detect diseases such as cancer and other abnormalities using a microscope. This may include examination of samples collected from the uterine cervix (pap test), lungs, gastrointestinal tract or body cavities. The individual cells reflect the normal a...

Cyto technology Is the study of human cells to detect diseases such as cancer and other abnormalities using a microscope. This may include examination of samples collected from the uterine cervix (pap test), lungs, gastrointestinal tract or body cavities. The individual cells reflect the normal and abnormal morphology of the tissue from which they are derived. Inflammatory Reparative process Cellular alterations: Cellular adaptation Cell death FACTORS THAT DETERMINE THE APPEARANCE OF CELLS Type of the technique used. Level of cell maturation at the time of cell collection. Nature of the parents tissue: soft tissue, cyst, or solid organ. Medium of the exfoliated cells. Interval between the stain of the exfoliated cells and collection of samples. Type of fixative, stain, and processing of the technique used. BASIC CELL STRUCTURE Membrane-bound structures that occur as functional independent units of life, or as structural or fundamental units in a biological tissue specialized to perform a particular function. There are between 10-100 trillion cells in an adult human. Tissues An aggregate of cells in an organism that have similar structure and function. Types include epithelial, connective, muscle, haematopoietic and nervous. Tissues that work in unison to carry out a specific set of functions form an organ. TISSUE OF INTEREST (EPITHELIA) Tightly cohesive sheets of cells. Covers internal and external surfaces Nomenclature and classification of different types is based on shape and arrangement of cells in one or more layers ROLE Protection Secretion Absorption TYPES OF EPITHELIA CELLS Simple epithelia- one layer of cells Subdivided into simple squamous, simple cuboidal and simple columnar. (Endothelium and Mesothelium). Stratified epithelia- Composed of two or more cell layers Subdivided stratified squamous, stratified cuboidal and stratified columnar (Keratinising and non-keratinising) Special categories- pseudostratified and transitional epithelium EARLY ORIGINS OF CYTOLOGY The history and development cytology as a diagnostic discipline cannot be discussed without reference to those individuals who developed the microscope. Antonie Philips van Leeuwenhoek (1632-1723)- one of the first microscopists and microbiologists Robert Hooke (1635-1703) -- used his microscope to study the ancient cells in fossilized wood. Carl Zeiss and August Kohler- (Read on this one) DEVELOPMENT OF CYTOLOGY Q Papanicolaou (Dr. Pap)- was a pioneer in cytopathology and inventor of the "Pap smear" for early detection of uterine cancer. In 1942 he developed the staining method of choice called Papanicolaou. Influential in the acceptance of cytology as a clinical tool in diagnosis and management of patients Based on his study of the female genital tract TERMINOLOGIES Smear: Specimen spread on a slide surface to facilitate microscopic observation. This is the standard method of specimen preparation in exfoliative cytology. Abnormal smear: A smear which shows cells which are not typically normal or where precancerous or cancerous cells are identified. Adequate smear: A specimen which is deemed satisfactory for evaluation by the laboratory. Biopsy: Removal of a sample of tissue from the body for examination under a microscope. Cervical cancer: Cancer of the cervix. Cancer cells have spread beyond the natural basement membrane boundary of the cervical skin. Cervical cancer can be of squamous origin (approximately 85%) or glandular/ adeno origin (approximately 15%). Cervical cytology: A microscopic examination of a single layer of cells scraped from the surface of the cervix. Cervical ectropion/eversion: Occurs when the inside of the cervical cells (columnar) evert on to the surface of the cervix; a red roughened area may appear on the cervix. This is a normal hormonally influenced change. Cervical intraepithelial neoplasia: CIN is not cancer but is the histological term referring to the abnormal growth of precancerous cells in the surface layers of the cervix. It describes, varying degrees of abnormality of the cells within and confined to the epithelium. There are three grades of CIN: CIN 1, CIN 2, CIN 3. Diagnostic smear: A smear taken outside of the normal screening intended as part of the diagnostic assessment of a woman who has signs and symptoms which might indicate cervical cancer. Dyskaryosis: Term used in cytology to describe nuclear abnormality in cervical cells. Dyskaryotic cells are classified as mild, moderate, severe and correlates with the histological terms of CIN1, CIN 2, CIN 3. Eligible for screening: Women aged 25-60 years for whom cervical check is recommends. Failsafe: The action taken by the clinically responsible doctor and programme office to ensure a smear results is appropriately followed-up. False negative: The result when the test indicates the absence of the disease in an individual where it is actually present. Human papilloma virus or HPV: A group of wart viruses of which a high proportion are sexually transmitted. Over 100 different types of HPV have been identified and each is known by number types 6 and 11 are associated with genital warts and types 16 and 18 are associated with high grade lesions. Liquid based cytology: the placement of harvested cervical cells into a special transport solution for sending to the laboratory where the slide is made ready for examination. Large loop excision of the transformation zone or LLETZ: Is a diagnostic and /or treatment method to remove the cervical areas of abnormality. The procedure involves removal of the entire transforming zone using a thin wire electrode charged with a low- voltage; high frequency, alternating current and produces a tissue specimen suitable for histologic analysis in most circumstances. It is sometimes called loop electrosurgical excision procedure (LEEP). Normal smear: A smear result that is reported to be within normal limits Opportunistic smear: A smear done when the opportunity presents irrespective of the woman's cervical check eligibility or screening requirements. Pap test: Another name for a 'smear test' named after George Papanicolau, who invented the process of staining cells on a slide in preparation for the examination under a microscope. Sensitivity: The ability of a test to be detect in all individuals in whom it is present. Squamous: A type of multi-layers cells, which line the vagina and the outer layer of the cervix. Squamous cell carcinoma: The most common form of cervical cancer. Unsatisfactory smear: A smear that cannot be safety read and report by the laboratory usually because there are insufficient cells or cells are obscured by exudates, polymorph or menstrual debris. VAIN: Vaginal Intraepithelial Neoplasia. Validity: The accuracy of the screening test in distinguishing those who have and those who do not have the disease in the symptomatic population. Vault smear: A smear taken from the top of the vagina after a total hysterectomy. VIN: Valval Intraepithelial Neoplasia. Exfoliative Cytology Abrasive Cytology Fine Aspiration Cytology Exfoliative cytology: Entails the microscopic examination and interpretation of cells which are shed (exfoliated) spontaneously from epithelial surfaces of the body, or which may removed from each from such surfaces or membranes by physical means. Natural covering epithelium: skin, urinary tract, vagina, and cervix. Glandular epithelial secretion: Breast (Nipple secretion). Sputum Urine Exudates and transudate: Pleural fluid Peritoneal fluid Pericardial fluid Joint fluid CSF Scrapings from cervix, vagina, oral cavity, and skin Brushing and lavage: bronchi, GIT, and urinary tract Fine needle aspiration (FNA) for: Body cavity fluid: pleural, pericardial & peritoneal fluids Cysts: neck, breast & ovary Solid tissue: body organs, tumors & other swell Early detection of unsuspected diseases (malignant or pre-malignant lesions). Confirmation of suspected diseases without surgical trauma. Diagnosis of hormonal imbalance. Useful in following up the course of disease or monitoring therapy. Advantages of Cytopathology Rapid diagnosis - Inexpensive - Simple It is better in evaluating the infectious diseases. Supplement or replace frozen section or biopsy No injury to tissue allowing repeated sampling It is better for hormonal assay Cytopathological smear cover a wider surface than that involved in surgical biopsy. Disadvantages of Cytopathology Interpretation of the morphological cellular changes is based only on individual cell observation. Not always final diagnosis, so it is confirmed by histopathology in some cases. Not determine the size and type of lesion of some cases. TECHNIQUES IN THE STUDY OF EXFOLIATIVE CYTOLOGY There are two main techniques involved in the study of exfoliative cytology: The study of direct smears of the specimen without centrifugation The study of concentrated material (e.g., sediment) NB: Concentration is accomplished by centrifugation or membrane filtration. The latter is not as common in laboratories of developing countries. Body fluids which are watery and dilute need to be concentrated. ABRASIVE CYTOLOGY Dislodges cells from body surfaces Imprint Scraping Endoscopic scraping from mucosal surfaces Swab FINE NEEDLE ASPIRATION CYTOLOGY This is a technique used to obtain material from organs that do not shed cells spontaneously. Superficial nodules and organs-easily targeted It is valuable in diagnosis of lesions of the breast, thyroid, lymph nodes, liver, lungs, skin, soft tissues and bones Deep-seated or impalpable lesion- Ultrasound, computerised tomography (CT). APPLICATIONS OF CYTOLOGY As a screening tool in populations of apparently healthy people who are at risk of a particular disease. Example Cervical cytology As a diagnostic tool in symptomatic patient Example application in non-gynaecological cytology.