What is cytology?

Cytology is the exam of a single cell type, as often found in fluid specimens. It's mainly used to diagnose or screen for cancer. It's also used to screen for fetal abnormalities, for pap smears, to diagnose infectious organisms, and in other screening and diagnostic areas.

The cells to be examined may be taken through the following methods:

• Scraping or brushing the tissue surface, such as during a pap smear

• Collecting body fluids, such for urine or respiratory phlegm

• Fine-needle aspirations. This is removing cells by drawing them through a fine needle, such as abdominal fluid in ascites, pleural fluid from the lungs, or cerebrospinal fluid from the spinal canal. 

• Other types of tissue biopsy 

Cytology is different from histology. Cytology generally involves looking at a single cell type. Histology is the exam of an entire block of tissue.