MyPathologyReport
December 7, 2023

In pathology, nuclear atypia is used to describe a nucleus that is abnormal in size, shape, or colour when examined under a microscope. The nucleus (the term nuclei is used to describe more than one) is the part of the cell that holds the genetic material or DNA. A cell may be described as showing nuclear atypia if its nucleus is larger, hyperchromatic (darker), has an irregular shape, or if the chromatin (genetic material) within the nucleus is clumped together or prominent. A single large clump of genetic material is called a nucleolus and they are frequently seen in these abnormal cells.

Nuclear atypia can be caused by changes that start inside the cell or from factors in the environment outside of the cell. Changes inside the cell include genetic abnormalities that cause the cell to grow and develop abnormally. These kinds of changes can lead to cancer over time. Factors in the environment include inflammation, viral infections, radiation, medication-induced changes, or tissue injury as a result of trauma, stress, or decreased blood flow.

Does nuclear atypia mean cancer?

No. Nuclear atypia does not mean cancer. Although this term is often used to describe malignant (cancerous) and precancerous cells, it can also be used to describe abnormal but benign (non-cancerous) cells.

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About this article

This article was written by doctors to help you read and understand your pathology report. Contact us if you have questions about this article or your pathology report. For a complete introduction to your pathology report, read this article.

Other helpful resources

Atlas of pathology