Last Updated: September 30, 2018
A hamartoma is a benign, noncancerous growth consisting of an abnormal mixture of native tissue. Although this tumor-like lesion resembles a neoplasm, it does not exhibit neoplastic tendencies such as accelerated growth, local invasion of surrounding tissues, or metastatic spread.
Hypothalamic hamartomas are exceedingly rare developmental anomalies classically associated with endocrine abnormalities and epilepsy. They consist of a mixture of hyperactive neuronal and glial cells arising from the floor of the third ventricle.
Their true incidence is unknown, but is estimated at one in 50,000 to one in one million. Although classically associated with gelastic seizures, hypothalamic hamartomas are also responsible for several other types of more debilitating medically refractory seizures. Endocrine abnormalities, including central precocious puberty, have also been implicated.
Behavioral, psychiatric, and cognitive impairments appear to have a higher incidence in this patient population as well. In their extreme form, hypothalamic hamartomas lead to disabling epi...