What it means
Mass is a descriptive word for a lump that takes up space and may push nearby tissue aside. In the lungs, radiologists use it for a spot larger than 3 cm, and call anything 3 cm or smaller a nodule. Elsewhere, such as in the breast, kidney or soft tissues, mass means a distinct lump of any size. It describes what the radiologist sees, not what it is made of.
When it matters
A mass can be harmless, such as a fatty lump called a lipoma or a fibroid in the uterus. It can also be cancer. Radiologists look at the edges, what the mass contains, its blood supply and whether it has grown. Some masses can be identified on the scan alone. Others need another scan or a biopsy, a small tissue sample, to know for sure.
Questions to ask your doctor
- What does the radiologist think this mass most likely is?
- Which features of the mass are reassuring or concerning?
- Does it need another scan or a biopsy, and how soon?
