Untitled Quiz

Learning Objectives

• An introductory background to cytology practice is important
• Identification key components in cytology
• Explore its role in the diagnostic pathology.

Early Origins of Cytology

• Cytology's history and development as a diagnostic discipline is related to those who developed the microscope
• Anton van Leeuwenhoek (1632-1723) contributed to cytology
• Robert Hooke (1635-1703) contributed to cytology via the cell
• Carl Zeiss and August Kohler also contributed

Cell: Conservation and Diversity

• Common cellular features: nucleus, cytoplasm, membrane,organelles.
• Diversity is aligned with function
• Size and shape are part of diversity
• Receptors and pathways are diverse

Cell: Lifecycle

• Cells are either dividing or non-dividing
• Longevity varies among cells
• The cell cycle is regulated and controlled

Tissues

• Tissues are cell aggregates in an organism with 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

Epithelial Tissues

• Epithelial tissues are tightly cohesive sheets of cells, covering internal and external surfaces
• Nomenclature and classification of different types is based on shape and arrangement of cells in one or more layers
• Function include Protection, Secretion & Absorption

Classifications of Epithelia

• Simple epithelia consist of one layer of cells
• Simple epithelia are subdivided into simple squamous, simple cuboidal and simple columnar, (Endothelium and Mesothelium)
• Stratified epithelia- Composed of two or more cell layers
• Stratified epithelia are subdivided into stratified squamous, stratified cuboidal and stratified columnar (Keratinising and non-keratinising)
• Pseudostratified and transitional epithelium are special categories

Background: Cytology in clinical practice

• Cytology is the study of the microscopic appearance of cells
• Identify type of cells normally present in different areas of the body
• Detect changes in the morphology of cells
• Identify the presence of abnormal cells

Development of Cytology

• George Papanicolaou was 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

Classifications in cytology

• Exfoliative cytology is a type
• Abrasive cytology is a type
• Fine Needle Aspiration cytology is a type

Exfoliative Cytology

• The study of cells that have been shed or removed from the epithelial surface of various organs
• Normal cells are cohesive in nature but exfoliated when they attain maturation
• Cells are recovered either by natural secretions or artificial means (lavage)
• Examples are; Urine, CSF Sputum, Effusions in body cavities (pleura, pericardium,peritoneum )

Abrasive Cytology

• Dislodges cells from body surfaces
• Imprint cytology is used
• Scraping cytology is used
• Endoscopic scraping from mucosal surfaces
• Swab cytology is used

Fine Needle Aspiration Cytology

• Used to obtain material from organs that do not shed cells spontaneously
• Superficial nodules and organs are easily targeted
• Valuable in diagnosis of lesions of the breast, thyroid, lymph nodes, liver, lungs, skin, soft tissues and bones
• Deep-seated or impalpable lesion needs Ultrasound, computerised tomography (CT)

Main Groupings of Cytology

• Gynaecological cytology includes Cervical cytology
• Non-gynaecological cytology include: Breast, Thyroid, Lymph nodes, Body fluids: Urine, pleural, peritoneal, pericardial etc

Applications of Cytology

• Used As a screening tool in populations of apparently healthy people who are at risk of a particular disease. Example: Cervical cytology
• Used as diagnostic tool in symptomatic patient. Example application in non-gynaecological cytology

Advantages of Cytopathology

• Simple, offers rapid diagnosis and is inexpensive
• Supplement or replace frozen section or biopsy
• No injury to tissue allowing repeated sampling
• Cytopathological smear cover a wider surface than that involved in surgical biopsy

Some Demerits

• Interpretation of the morphological cellular changes is based only on individual cell observation
• Not always finally diagnosis, requires confirming histopathology in some cases
• Can't determine the size and type of lesion of some cases

The Cytologist job

• Differentiate between normal and abnormal cells
• Search for and as far as possible classify, neoplastic cells in clinical specimens
• Provide high quality patient care and procuring of good quality specimen
• Your sample is as good as your result

The Cytologist’s Job: Challenge

• Maximising tissue/cell retrieval for multiple tests
• Ensuring that the quality of material obtained will be satisfactory
• Standardising procedures for sample collection

What is an adequate specimen?

• An adequate specimen is the one that contains cells that are representative of the site sampled
• If the site is a tumour, then tumour cells are the only representative cells
• 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

Sampling Error

• Occurs 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

Storage and Transport of samples

• Cytological samples are nearly always fixed and processed promptly after sample collection, leading to a well-preserved nucleic contents
• Most appropriate specimen containers must be used
• The right method of preservation of the specimen should be adhered to
• Utilise the best mode of transport
• All unfixed specimens must be transported immediately
• Specimen can be mixed with appropriate transport media or a fixative, for Example, CytoRich Red and Cytolyt
• Store specimen at 4º Celcius