Presacral masses in children: presentation, aetiology and risk of malignancy.
Bartels SA, van Koperen PJ, van der Steeg AF, Deurloo EE, Bemelman WA, Heij HA. Presacral masses in children: presentation, aetiology and risk of malignancy. Colorectal Dis. 2011 Aug; 13(8):930-4.