November 6, 2023


In pathology, the term pleomorphic is used to describe a group of cells that are very different from each other in size, shape, or colour. For example, the cells in a tissue sample would be described as pleomorphic if some of the cells in a tissue sample were small while others were very large. While the term, pleomorphic can be used to describe the look of the entire cell, it is more often used to describe the look of the nucleus (the part of the cell that holds the genetic material).

Pleomorphic cells are often seen in tumours. Pleomorphic cells are more likely to be seen in malignant (cancerous) tumours although they can also be seen in some benign (non-cancerous) tumours. These cells can also be seen after an injury in a group of reactive cells.

The word pleomorphic is not a diagnosis. It is a description of the cells seen in the tissue sample. This description will be used in combination with other information to reach a diagnosis. Because these cells look very abnormal your pathologist may order additional tests such as immunohistochemistry to try to learn more about the cells.

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.

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