Objective: To report a rare case of gonadotroph adenoma accompanied by ovarian enlargement in a child.
Design: Case report.
Setting: A university hospital.
Patient(s): A 10-year-old Japanese girl with multiple cysts of both ovaries.
Intervention(s): Endocrinologic assays, immunohistochemical staining, ultrastructural observations, and in vitro analysis.
Main outcome measure(s): The endocrinologic assays showed an elevated serum FSH level. The tumor cells excised from the gonadotroph adenoma were immunohistochemically positive for antihuman FSH monoclonal antibody. When cultured in vitro, the tumor cells secreted FSH in the primary culture.
Result(s): The gonadotroph adenoma produced FSH. After transsphenoidal surgery, both ovaries decreased in size.
Conclusion(s): The ovarian enlargement was induced by endogenous FSH from the gonadotroph adenoma. To our knowledge, this is the first reported case of gonadotroph adenoma accompanied by ovarian enlargement in childhood or adolescence.