ESPE Abstracts

Background: Gonadoblastoma is a rare tumour of the gonads presenting in childhood or adolescence. It is a lesion composed of a mixture of germ cells at different stages of maturation, with low malignant potential. It is associated with disorders of sex development (DSD), most commonly Turner mosaic syndrome with Y chromosome material (TMSY), and 46XY gonadal dysgenesis (GD). Little is known about the natural history and incidence of this rare tumour.

Objective and hypotheses: To determine the incidence and clinical features of gonadoblastoma presenting before age 16 years in the Irish Republic (RoI) from 1999 to 2013 inclusive.

Method: A retrospective review of children and adolescents with a diagnosis of gonadoblastoma was undertaken using the records of the National Cancer Registry Ireland (NCRI) and the Departments of Endocrinology, Pathology and Surgery at the main children’s hospitals. All children in Ireland requiring gonadectomy are referred to the same tertiary referral centre thus anticipating good case ascertainment. Clinical case notes and histopathological findings were reviewed.

Results: Eight cases of gonadoblastoma were identified over the 15 year period. All were phenotypically female. Five cases had TMSY (age range gonadoblastoma diagnosis 6 months–14 years), bilateral in two cases. Three cases of 46 XY GD were aged 4 months, 8 and 9 years at diagnosis of gonadoblastoma (unilateral). In one case of 46 XY GD with SRY deletion, clinical symptoms (age eight) prompted gonadectomy. Histology showed unilateral dysgerminoma and contralateral gonadoblastoma. In all other cases gonadoblastoma was diagnosed on elective gonadectomy.

Conclusion: The incidence of gonadoblastoma in RoI over the past 15 years is eight, giving a population incidence of 0.08 per 10 000 births. To our knowledge this is the first population incidence rate of GB in children reported. Due to the low age of gonadoblastoma cases observed in this cases series, the recommendation for elective gonadectomy in high risk conditions is supported.