Hamartoma of the Tuber Cinereum

Hamartoma of the Tuber Cinereum

MR – Between the lamina terminalis and optic chiasm anteriorly and the mamillary bodies is focal thickening of the tuber cinereum which is iso- to hypointense on sagittal T1 image. Also note, thinning of the posterior corpus callosum and downward displacement of the cerebellar tonsils.

Hypothalamic hamartomas are developmental malformations consisting of tumorlike masses located in the tuber cinereum of the hypothalamus. Most patients present in the first or second decade of life, with boys being more commonly affected than girls. There are 2 types of hypothalamic hamartomas, parahypothalamic hamartomas and intra-hypothalamic hamartomas. Parahypothalamic hamartomas are pedunculated and associated with precocious puberty. Intrahypothalamic hamartomas are sessile masses with a broad attachment to the hypothalamus and are associated with gelastic seizures. At pathologic analysis, hypothalamic hamartomas contain nerve cells that resemble those of the normal hypothalamus, along with normal glial cells. At MR imaging hamartomas of the tuber cinereum are isointense or mildly hypointense on T1-weighted images and iso- to hyperintense on T2-weighted images, with no contrast enhancement or calcification. Stability of the lesion strongly supports the diagnosis of hypothalamic hamartoma.

Saleem SN, Said AM and Lee DH. Lesions of the Hypothalamus: MR Imaging Diagnostic Features. Radiographics (2007); 27:1087-1108.

John Quick MD