Cytology is the study of individual cells of the body, as opposed to histology which is the study of whole human tissue itself. Strictly speaking, cytology is the study of normal cells and cytopathology is the examination of cells in the context of disease, which is really what we’ll be talking about but “cytology” is used by many people as shorthand for both, so that’s what we’ll do here. The human body is made up of millions of cells and these can be sampled and looked at under the microscope, after suitable preparation, to help diagnose medical conditions.
This involves looking at the individual cells for abnormal changes of both the nucleus and also the cytoplasm (body) of the cell. The nucleus contains the genetic material that controls the cell, and determines what type of cell it will become, but also controls its behavior. Changes in the nucleus, gauged by changes in its size, shape and appearance of the nuclear material (chromatin) can be assessed by a trained cytologist and this can be used to diagnose possible cancer and also pre-cancer. “Pre-cancer” means cell changes which if left untreated may develop into a true cancer. Cytology can also be used to diagnose many non-cancerous medical conditions such as infections and systemic diseases.
There are two main branches of cytology. There are those involved with the assessment of pre-cancerous and, occasionally, cancerous, changes of the cervix (mouth of the womb) such as in cervical cancer screening, which are generally referred to as gynaecological cytology.
There is also the use of cytology to diagnose medical conditions in other tissues of the body, generally referred to as non-gynaecological or diagnostic cytology. Samples received by laboratories will include samples which can be taken by collection (e.g. a urine sample) or by brushing the area with a sampling device (e.g. cervical sample, some lungs samples). Others are taken by use of a needle inserted into a body site (termed a fine needle aspiration or FNA) which can be done for nearly every part of the body.
Cytology is widely used in medicine for the prevention and diagnosis of disease. In 2016 over 3,000,000 cervical screening samples were taken in England as part of the cervical screening programme. There is no accurate figure available for the use of cytology in other tissues, but it is used on a daily basis to help diagnose cancerous and non-cancerous conditions of the respiratory, urinary, and gastro-intestinal tracts as well as thyroid gland, salivary glands and lymph nodes to name but a few.
Staff in cytology
There are many staff working in laboratories involved with aspects of a cytology service. These are mix of a medically qualified medical pathologists, and health care professionals, many coming into the profession as post graduates who have specifically trained in the area of cytology.. A large number also work (or have worked) in histology, and there is much overlap of the skills and staff between the two areas.
Staff are involved in areas such as:
Sample receipt and preparation
Cytology screening and reporting
Clinical onsite adequacy and triage
Clinical meetings (often termed Multidisciplinary Meetings - MDTs)
Royal College of Pathologists
Contact the BAC for queries or comments on cytology issues