Introduction to Cytology - Cytology Overview PDF

INTRODUCTION TO CYTOLOGY Dr. Ernest Adankwah Department Medical Diagnostics 2/17/25 1  Learning Objectives n To give an introductory background to cytology practice n To explore key components in cytology...

INTRODUCTION TO CYTOLOGY Dr. Ernest Adankwah Department Medical Diagnostics 2/17/25 1  Learning Objectives n To give an introductory background to cytology practice n To explore key components in cytology n To explore its role in the diagnostic pathology 2/17/25 2  Early Origins of Cytology n The history and development cytology as a diagnostic discipline cannot be discussed without reference to those individuals who developed the microscope Anton van Leeuwenhoek (1632-1723) Robert Hooke (1635-1703) – Cell Carl Zeiss and August Kohler 2/17/25 3  Cell: Conservation and Diversity § Common features: Nucleus, cytoplasm, membrane, organelles. § Diversity: Aligned with function Size, shape Receptors and pathways 2/17/25 4  Cell: Life cycle n Dividing and Non dividing n Longevity n Cell cycle and control 2/17/25 5  TISSUES n An aggregate of cells in an organism that have similar structure and function. n Types include epithelial, connective, muscle, haematopoietic and nervous. n Tissues that work in unison to carry out a specific set of functions form an organ. 2/17/25 6  EPITHELIA TISSUES n Tightly cohesive sheets of cells. Covers internal and external surfaces n Nomenclature and classification of different types is based on shape and arrangement of cells in one or more layers n Protection, Secretion & Absorption 2/17/25 7  Classification of Epithelia n Simple epithelia- one layer of cells Subdivided into simple squamous, simple cuboidal and simple columnar. (Endothelium and Mesothelium). n Stratified epithelia- Composed of two or more cell layers. Subdivided stratified squamous, stratified cuboidal and stratified columnar (Keratinising and non-keratinising) n Special categories- pseudostratified and transitional epithelium 2/17/25 8  BACKGROUD: Cytology in clinical practice What is cytology? n The study of the microscopic appearance of cells n Identify type of cells normally present in different areas of the body n Detect changes in the morphology of cells n Identify the presence of abnormal cells 2/17/25 9  Development of Cytology n George Papanicolaou n Influential in the acceptance of cytology as a clinical tool in diagnosis and management of patients n Based on his study of the female genital tract 2/17/25 10  Classification in cytology n Exfoliative cytology n Abrasive cytology n Fine Needle Aspiration cytology 2/17/25 11  Exfoliative Cytology n It is the study of cells that have been shed or removed from the epithelial surface of various organs n Normal cells are cohesive in nature but exfoliated when they attain maturation n Cells are recovered either by natural secretions or artificial means (lavage) n For example; Urine, CSF Sputum , Effusions in body cavities (pleura, pericardium, peritoneum ) 2/17/25 12  Abrasive Cytology Dislodges cells from body surfaces n Imprint n Scraping n Endoscopic scraping from mucosal surfaces n Swab 2/17/25 13  Fine Needle Aspiration Cytology n This is a technique used to obtain material from organs that do not shed cells spontaneously. n Superficial nodules and organs-easily targeted n It is valuable in diagnosis of lesions of the breast, thyroid, lymph nodes, liver, lungs, skin, soft tissues and bones n Deep-seated or impalpable lesion- Ultrasound, computerised tomography (CT). 2/17/25 14  Fine Needle Aspiration Cytology FNA procedure without aspiration FNA of the thyroid gland using a syringe holder 2/17/25 15  Fine Needle Aspiration Cytology Ultrasound guided FNA of breast 2/17/25 16  Main Groupings of Cytology Gynaecological cytology n Cervical cytology Non-gynaecological cytology n Breast n Thyroid n Lymph nodes n Body fluids: Urine, pleural, peritoneal, pericardial etc, 2/17/25 17  Applications of Cytology n As a screening tool in populations of apparently healthy people who are at risk of a particular disease. Example: Cervical cytology n As a diagnostic tool in symptomatic patient. Example application in non-gynaecological cytology. 2/17/25 18  Advantages of Cytopathology n Simple, offers rapid diagnosis and is inexpensive n Supplement or replace frozen section or biopsy n No injury to tissue allowing repeated sampling n Cytopathological smear cover a wider surface than that involved in surgical biopsy 2/17/25 19  Some Demerits! n Interpretation of the morphological cellular changes is based only on individual cell observation. n Not always finally diagnosis, so it is confirmed by histopathology in some cases. n Does not determine the size and type of lesion of some cases. 2/17/25 20  The Cytologist Job n Differentiate between normal and abnormal cells n Search for and as far as possible classify, neoplastic cells in clinical specimens n High quality patient care and procuring of good quality specimen n Your sample is as good as your result 2/17/25 21  The Cytologist’s Job: Challenge n Maximising tissue/cell retrieval for multiple tests n Ensuring that the quality of material obtained will be satisfactory n Standardising procedures for sample collection 2/17/25 22  What is an adequate specimen? n An adequate specimen is the one that contains cells that are representative of the site sampled n If the site is a tumour, then tumour cells are the only representative cells n If the site happens to be a normal healthy cervix then an adequate cervical sample should contain cells that are representative of the area that is most susceptible to neoplastic change, that is, the transformation zone. 2/17/25 23  Sampling Error § In terms of specimen collection for cytology Sampling error can be defined as the failure to collect cells that are representative of the site being sampled, to collect them in sufficient quantity to make a reliable diagnosis 2/17/25 24  Storage and Transport of samples n Cytological samples are nearly always fixed and processed promptly after sample collection, leading to a well-preserved nucleic contents n Most appropriate specimen containers must be used n The right method of preservation of the specimen n The best mode of transport 2/17/25 25  Storage and Transport of samples n All unfixed specimens must be transported immediately! n Specimen can be mixed with appropriate transport media or a fixative. Example CytoRich Red and Cytolyt n Store specimen at 40 C 2/17/25 26