Germinoma in a boy with precocious puberty: evidence of hCG secretion by the tumoral cells.

The present report concerns a 10-year-old boy in whom diabetes insipidus and short stature were the first manifestations of a suprasellar germinoma. Neuroradiological investigations performed when these symptoms appeared were negative. 2 years later, a rapid and early pubertal development was observed and related to secretion by the germinoma of human chorionic gonadotropin (hCG) identified immunohistochemically. This clinical evolution is unusual and indicates that plasma hCG measurements in patients with so-called idiopathic diabetes insipidus can be of clinical value in predicting the presence of an hCG-secreting tumor.