Breast -

Lobular carcinoma in situ (LCIS)

This article was last reviewed and updated on August 13, 2019.
by Jason Wasserman, MD PhD FRCPC

Quick facts:

  • Lobular carcinoma in situ (LCIS) is a condition caused by an increased number of cells in the glands of the breast.

  • Lobular carcinoma in situ is important because it is associated with an increased risk of developing breast cancer over time.

  • The types of breast cancer associated lobular carcinoma in situ are invasive lobular carcinoma and invasive ductal carcinoma.

The normal breast

Adult breast tissue is made up of small structures called glands which are arranged into groups called lobules. Under certain conditions, these glands can produce milk, which is transported to the nipple by a series of small channels called ducts.  

 

The inside of both glands and ducts is lined by specialized cells called epithelial cells which form a barrier called the epithelium. The tissue surrounding glands and ducts is called stroma and contains long, thin cells called fibroblasts.

What is lobular carcinoma in situ?

Lobular carcinoma in situ (LCIS) is a condition caused by an increased number of epithelial cells in the glands of the breast.

 

Lobular carcinoma in situ is not a cancer. However, the diagnosis of lobular carcinoma in situ is associated with an increased risk of developing breast cancer over time. The increased risk applies to both breasts, not just the breast diagnosed with lobular carcinoma in situ.

The two types of breast cancer associated with lobular carcinoma in situ are invasive ductal carcinoma and invasive lobular carcinoma.

 

The diagnosis of lobular carcinoma in situ is usually made after a small sample of tissue is removed in a procedure called a core needle biopsy. Lobular carcinoma in situ is also commonly diagnosed after surgery is performed for another disease such as invasive ductal carcinoma or ductal carcinoma in situ.

Histologic type

There are two different types of lobular carcinoma in situ based on how the cells look when examined under a microscope.

 

  1. Classic type - This is the most common type of lobular carcinoma in situ. The cells are small and they travel through the tissue as single cells (they are not attached the other abnormal cells).

  2. Pleomorphic type - The cells in the pleomorphic type are larger and more abnormal looking than the cells in the classic type. The nucleus of the cell (the part of the cell that holds most of the genetic material) is also darker and larger than the nucleus in the classic type.

Why is this important? Both classic and pleomorphic lobular carcinoma in situ are associated with an increased risk of breast cancer but the risk is higher if the cells are pleomorphic.

Nuclear grade

The nucleus is the part of the cell that contains most of the cells genetic material (the DNA). The abnormal cells in lobular carcinoma in situ are given a nuclear grade between 1 and 3 based on the shape and size of the nuclei and the number of abnormal cells dividing to creating new cells (mitotic figures).

Instead of a numerical grade (1 through 3), some pathology reports divide the grade in low, intermediate, and high. 

Why is this important? The nuclear grade is important because grade 3 (high grade) lobular carcinoma in situ is associated with a higher risk of cancer compared to grade 1 (low grade) lobular carcinoma in situ.

Comedonecrosis

Necrosis is a type of cell death. Comedonecrosis is a special type of necrosis sometimes seen in lobular carcinoma in situ. In comedonecrosis, the dead cells are in the centre of a duct and surrounded by living cells.

 

Why is this important? Comedonecrosis is more likely to be seen in high grade lobular carcinoma in situ. It is also associated with an increased risk of cancer compared to lobular carcinoma in situ without comedonecrosis.​

  • Facebook
  • Twitter

Copyright 2017 MyPathologyReport.ca

For more information about this site, contact us at info@mypathologyreport.ca.

Disclaimer: The articles on MyPathologyReport are intended for general informational purposes only and they do not address individual circumstances. The articles on this site are not a substitute for professional medical advice, diagnosis or treatment and should not be relied on to make decisions about your health. Never ignore professional medical advice in seeking treatment because of something you have read on the MyPathologyReport site. The articles on MyPathologyReport.ca are intended for use within Canada by residents of Canada only.

Droits d'auteur 2017 MyPathologyReport.ca
Pour plus d'informations sur ce site, contactez-nous à info@mypathologyreport.ca.
Clause de non-responsabilité: Les articles sur MyPathologyReport ne sont destinés qu’à des fins d'information et ne tiennent pas compte des circonstances individuelles. Les articles sur ce site ne remplacent pas les avis médicaux professionnels, diagnostics ou traitements et ne doivent pas être pris en compte pour la prise de décisions concernant votre santé. Ne négligez jamais les conseils d'un professionnel de la santé à cause de quelque chose que vous avez lu sur le site de MyPathologyReport. Les articles sur MyPathologyReport.ca sont destinés à être utilisés au Canada, par les résidents du Canada uniquement.