In a study of Tikka et al. from the Queen Elizabeth University Hospital, Glasgow, United Kingdom 540 patients on the database 28 (5.2%) showed spontaneous regression with a mean follow-up of 122 months. Mean absolute and relative regression was 3.9 mm and 25.7%, respectively. 60% of tumors showed gradual regression while 25% showed growth followed by regression. Regressing VS had a significantly larger size than the control group; while the regressing tumors were located further from the fundus than the control group. The remaining examined factors did not reach a statistical level of significance.
This is, the first study comparing a cohort of regressing tumors with a control group of growing VS. The finding that the location of tumors around the porous, is more common in regressing VS has implications for patients' counselling 1).