[A 10-kg ovarian mucinous cystadenoma in a 13 year-old girl]

A 13 year-old girl was admitted to hospital with abdominal pain and weight gain. The physical examination showed pronounced abdominal distension, but slim extremities. A magnetic resonance imaging scan revealed a left cystic ovarian tumour. The ovarian tumour was removed and the weight turned out to be 10.3 kg. Pathology showed a borderline mucinous cystadenoma. Ovarian tumours represent less than 2% of all tumours in girls under the age of 16. In this age group 50% of the ovarian tumours are neoplastic and 60% derive from the surface epithelia of the ovary.