Hypothalamic Hamartoma: A Rare Cause of Precocious Puberty

Abstract

Aims: To highlight the characteristic magnetic resonance imaging (MRI) features of hypothalamic hamartoma and its role in the diagnosis of central precocious puberty in children. Presentation of Case: A 9-year-old girl presented with progressive breast development, pubic hair growth, and accelerated linear growth. Clinical examination revealed Tanner stage IV development. Hormonal assessment showed elevated luteinizing hormone (0.92 IU/L) and estradiol (25 pg/mL), with normal follicle-stimulating hormone and 17-hydroxyprogesterone levels. Brain MRI demonstrated a small, well-circumscribed, non-enhancing lesion arising from the tuber cinereum, with signal intensity similar to grey matter and no mass effect on the optic chiasm or third ventricle. These findings were consistent with a hypothalamic hamartoma. The patient was treated with leuprorelin acetate, with favourable clinical and psychological evolution. Discussion: Hypothalamic hamartoma is a rare congenital, non-neoplastic malformation and an important structural cause of central precocious puberty. Its characteristic MRI appearance, including its location, signal intensity, lack of enhancement, and absence of significant mass effect, usually allows a confident diagnosis and helps differentiate it from other suprasellar lesions. Conclusion: Recognition of the typical MRI features of hypothalamic hamartoma is essential for accurate diagnosis and can prevent unnecessary invasive investigations. Early recognition also allows appropriate endocrine management and favourable clinical outcomes.