Cytology

Cytology

Definition

Cytology is the examination of individual cells and small clusters of cells, and may be used for the diagnosis and screening of diseases, including cancers. Cytology can also be referred to as cytopathology.

Purpose

Diagnostic tests are used to detect a disease in individuals who have signs, symptoms, or some other abnormality that is indicative of disease. A screening test identifies those who might have a certain disease, sometimes before they develop any symptoms, but does not absolutely prove that disease is present. If a screening test is positive, a diagnostic test can be used as follow-up to verify the diagnosis.

Precautions

Procedures to gather cells for cytology are often less invasive than other forms of biopsy , and therefore may cause less discomfort, be less likely to result in serious complications, and cost less to perform. In some situations, however, where a piece of tissue is removed rather than individual cells, a different type of biopsy may be required to confirm the cytologic diagnosis.

Description

Samples for cytology can be obtained in more than one way. Fine needle aspiration (FNA) is a type of biopsy in which tumor samples are taken through thin needles.

Scrape or brush cytology is another technique in which cells are scraped or brushed from the organ or tissue being tested. Samples from the esophagus, stomach, bronchi (breathing tubes that lead to the lungs), and mouth can be obtained using this procedure.

How a cytology sample is processed depends on what type of sample it is. A doctor can smear a sample directly on a glass microscope slide. The slide is then stained and viewed by a cytopathologist. In other cases, the fluid is concentrated before being smeared and stained on a slide. This is especially useful for dilute samples such those from body cavities.

Most routine cytology results are available one or two days after the sample is received in the laboratory. There are many reasons why some results take longer to return, such as if special stains are required to confirm a diagnosis.

Preparation, Aftercare, and Risks

Because this analysis is performed on cells that had been already gathered during initial diagnostic procedures, there is no additional preparation, aftercare, or risks for the patient. The only procedure, aftercare, or risks to note would be those associated with the sample collection itself.

Normal results

A cytopathologist examines and identifies the normal and abnormal cells on the slide using a microscope.

Abnormal results

A pathologist reviews the cells identified as abnormal to decide on a diagnosis.

See Also Biopsy; Pap test

Resources

PERIODICALS

Dahlstrom, Jane E., Gillian M. Langdale-Smith, and Daniel T.James. "Fine Needle Aspiration Cytology of Pulmonary Lesions: A Reliable Diagnostic Test" Pathology 33 (2001): 13-16.

ORGANIZATIONS

American Cancer Society. 1599 Clifton Road NE, Atlanta, GA30329. (404) 320-3333. <http://www.cancer.org>.

American Society for Clinical Pathologists (ASCP). 2100 West Harrison Street, Chicago, IL 60612. (312) 738-1336. <http://www.ascp.org.>.

American Society for Cytopathology (ASC). 400 West 9th Street, Suite 201, Wilmington, DE 19801. (302) 429-8802. <http://www.cytopathology.org.>.

College of American Pathologists (CAP). 325 Waukegan Road, Northfield, IL 60093. (800) 323-4040. <http://www.cap.org>.

International Academy of Cytology (IAC). 1640 East 50th Street, Ste. 20C, Chicago, IL 60615-3161. (773) 955-1406. <http://www.cytology-iac.org>.

Laura Ruth, Ph.D.

KEY TERMS

Biopsy

—Removing tissue from living patients for a diagnostic examination.

Cytology/cytopathology

—The study of cells or cell types.

Fine needle aspiration

—Removal of tissue or suspensions of cells using a small needle.

Pap smear

—A common cytology test used to screen for malignant and premalignant changes of the cervix.

QUESTIONS TO ASK THE DOCTOR

• What is a cytology test?
• How accurate is a cytology test?
• How long will it take to get cytology test results?