A child presents with gelastic seizures, precious puberty. MRI shows small pedunculated mass attached to tuber cinerum. What is the diagnosis?

Hypothalamic hamartoma : Most common brain lesion causing central precocious puberty. Consists of ectopically located neural tissue. May be associated with gelastic seizures (laughing spells). MRI - small pedunculated mass attached to cinerum or floor of 3rd ventiricle.