Mucinous cystadenoma of the ovary in perimenarchal girls.

Ovarian masses in children are an uncommon occurrence. They represent less than 2% of all tumours in girls less than 16 years of age. Mucinous tumours of the ovary occur principally in middle adult life and are extremely rare prior to menarche. To the best of our knowledge, there are only 13 previous cases of benign mucinous cystadenoma (MCA) of the ovary in perimenarchal girls reported in the literature. We present six cases of this rare tumour. We reviewed the charts of six patients who presented with large MCA of the ovary. The patient's ages ranged from 13 to 14 years (mean 13.6 years). Two were premenarchal and four were within 1 year of menarche. All children presented with marked abdominal distension and discomfort. Except for one child who had ultrasound scan alone, all the others had either CT or MRI scan as well. Ultrasound demonstrated a large multiloculated cystic mass arising from the pelvis reaching the level of the xiphoid. CT demonstrated an enormous mass occupying almost the entire abdomen. The mass was partly solid, partly cystic and the cystic elements were multiloculated in all patients. Three patients demonstrated contralateral hydronephrosis on imaging. Laparotomy revealed a tumour arising from the left ovary in five patients and from the right ovary in one. Several litres of fluid were aspirated in order to deliver the tumour from the abdomen. All patients underwent oophorectomy or salpingo-oophorectomy. Histology revealed benign MCA of the ovary in all cases. On follow up, ranging from 2.4 to 5 years, all patients were well with no evidence of recurrence. MCA in perimenarchal girls usually affects the left ovary. Although this tumour is rare, this diagnosis should be considered in 11 to 15-year-old girls presenting with a very large abdominal mass.