Introduction: Pituitary duplication is a rare congenital malformation, with fewer than 80 cases reported in the literature. It is often associated with midline malformations but can also occur in isolation. Central precocious puberty (CPP) is the most common endocrinological manifestation, but to date this has only ever been reported in female patients.

Case report: A 9-year-old boy presented with precocious puberty. His medical history was notable for ventricular septal defect. Physical examination showed Tanner stage P3 G2, a growth rate of 10 cm/year, and bone age of 12.5 years. A GnRH test confirmed CPP. Pituitary function was otherwise normal. MRI revealed ectopic pituitary duplication with two separate stalks, two ectopic posterior pituitary, tuberomammillary fusion, and vascular anomalies involving the basilar artery and vertebral vessels. The patient was treated with GnRH agonist therapy, which normalized growth and slowed bone maturation. Whole exome sequencing did not identify any pathogenic variants.

Conclusion: This is the first reported case of CPP in a male with pituitary duplication. The findings highlight the need for awareness of endocrine dysfunction, including CPP, in patients with pituitary malformations. The gender disparity of CPP in pituitary duplication remains unexplained, and further research into genetic and molecular mechanisms, notably Sonic Hedgehog signaling, is required to understand this association.