chapter  31
Hypothalamic neuronal hamartoma
ByMarc K. Rosenblum
Pages 10

The first account of what we now term the hypothalamic neuronal hamartoma was penned some 70 years ago by LeMarquand and Russell (1934) in their description of a child with precocious puberty of infantile onset and a mass involving the third ventricular floor. Attached to the tuber cinereum and right mammillary body, this contained aggregated neurons of fully mature appearance separated by myelinated nerve fiber bundles in modest number. Tuberal hamartomas of this sort have since come to be recognized as the most common organic cause of central precocious puberty (Pescovitz et al., 1986; Rivarola et al., 2001), have been implicated in a characteristic seizure disorder (‘gelastic’ epilepsy) typified by laughter-like vocalizations (Berkovic et al., 1988) and have emerged as defining manifestations of a malformative complex – the Pallister-Hall syndrome – linked to mutations involving the GLI3 gene on chromosome 7p13 (Kang et al., 1997; Johnston et al., 2005). Other components of this heritable disorder are detailed below (see Associated conditions and genetic features).