Cervical abnormalities: CIN3 and CGIN

What is CGIN?

Most women who have a cervical screening test (smear) have a normal result but, "for around one in 20 women, the test shows changes in cells” (NHS Cervical Screening leaflet, ‘Cervical screening – the facts’ March 2013). An abnormal result is not unusual. The changes in the cells or abnormal cells may need further investigation. Often the changes are due to inflammation or infection. It is important to remember that it is extremely rare for an abnormality found at screening to be cancer. 

The transformation zone is an area of the cervix where abnormal cells most commonly develop; they can be detected by cervical screening and colposcopy. Two different cervical cell types can become abnormal. The inside of the cervix (endocervix) is lined by glandular cells. The outside of the cervix (ectocervix) is lined by squamous cells. When abnormalities are diagnosed in the squamous cells (after further tests), these abnormalities are known as CIN (see ‘What is CIN?’). Abnormal cells can also develop in the inner part of the cervix – this is called CGIN.

The inner part of the cervix within the cervical canal has different glandular cells and, when these cells have abnormalities, these are called adenocarcinoma in situ or CGIN. It is less common to have abnormalities in the glandular cells (CGIN), but it has become more common in recent years. More than 1 in 10 cervical cancers are adenocarcinoma (10 to 15%) - Cancer Research UK 2014.

Audio onlyText only
Read below
CGIN stands for Cervical Glandular Intra-epithelial Neoplasia. It is an abnormality of the glandular tissue in the cervix. This abnormality is in the tissue extending into the womb from the transformation zone. CGIN is usually classified as low grade (mild) or high grade (severe). High grade CGIN is the equivalent of CIN3.

CGIN can be multi-focal – this means that more than one area is affected at one time, with normal tissue lying between them. As it can be difficult to monitor and assess this type of abnormality, further hospital based care is usually offered, often as an outpatient.

CGIN is not cancer but, if left untreated, these changes may develop into a type of cancer called adenocarcinoma (‘adeno’ means gland). A cervical screening test (smear) can also detect early cancer of the cervix, but very few women with an abnormal test result actually have cancer of the cervix.

Audio onlyText only
Read below

Last reviewed May 2014.
Last updated May 2014.


Please use the form below to tell us what you think of the site. We’d love to hear about how we’ve helped you, how we could improve or if you have found something that’s broken on the site.

Make a Donation to healthtalk.org

Find out more about how you can help us.

Send to a friend

Simply fill out this form and we'll send them an email