Polyps are benign growths which occur in any body cavity due to an overgrowth of the cells of the lining. When they occur in the endometrium, they can lead to irregular bleeding. They can usually be seen by vaginal ultrasound, but sometimes it is necessary to inject sterile saline into the uterus to identify them accurately. They rarely become malignant and are commonly seen in women over the age of 30. The only way to treat them is by surgery.