Mucinous neoplasm arising in a urachal cyst: a first in the pediatric population.

Urachal anomalies are relatively uncommon and result because of incomplete obliteration of the urachus prenatally. In children, urachal cysts and sinuses constitute the common presentations, and these can sometimes become secondarily infected. Malignant involvement of the urachus in the pediatric population is rare, and primary urachal adenocarcinoma is reported exclusively in adults. Herein, we present the case of an adolescent girl with a low-grade mucinous neoplasm arising in a urachal cyst and discuss its significance.