Cytology is the study of the structure and function of cells; the examination of cells under a microscope as used in the diagnosis of cancer.

There are a variety of procedures employed to obtain material for cytologic examination from fine needle aspiration of superficial or internal lesions to exfoliated cells obtained by aspiration, washing, brushing, smears, or scraping of vaginal secretions, sputum, urine, abdominal fluid, prostate secretions, etc. The more common techniques include:

Brushings - The procedure of brushing the lining of an organ for the purpose of obtaining cells

Punctures - Inserting a hollow needle into a cavity or organ for the purpose of removal of some portion of the contents (fluid, bone marrow, tissue)

Paracentesis - Surgical puncture of a cavity for aspiration of fluid, such as the abdominal cavity

Thoracentesis - Surgical puncture for aspiration of fluid from the chest

Scrapings - The procedure of scraping the lining of a structure with an instrument for the purpose of obtaining cells.

Swabs - Using a swab or similar device to obtain fluid and secretions which then can be used to make a smear.

Washings - The removal of fluid from a hollow organ or structure for the purpose of collecting any cells in the fluid which may be exfoliated.