Hamartomas of the tuber cinereum (Fig. 13.31) are congenital tumours composed of neurosecretory neurones and other neural tissue and which do not increase in size with time. They are frequently associated with true precocious puberty, often in patients younger than three years of age. These hamartomas are often connected with the posterior portion of the tuber cinereum or the mammillary body, or to the floor of the third ventricle by a stalk. In the past, a surgical approach has been used to excise them, but their location makes removal dangerous; furthermore, since they are so amenable to GnRH agonist therapy, surgical treatment is no longer appropriate. Immunohistochemical studies have shown that the hamartomas contain GnRH-containing neurones.
