Gynaecomastia in a patient with Peutz-Jeghers syndrome.

A prepubertal boy presented to our paediatric endocrinology clinic with long-standing, progressive bilateral gynaecomastia. The diagnostic evaluation to determine the underlying cause led to the identification of Peutz-Jeghers syndrome with associated testicular micro- and macrolithiasis. The young man was found to have prepubertal gonadotropin concentrations in the context of raised oestradiol levels. Altered sex steroid generation by the abnormal testes is the likely mechanism for the clinical presentation.