Case of the Week
Section Editors: Matylda Machnowska1 and Anvita Pauranik2
1University of Toronto, Toronto, Ontario, Canada
2BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
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August 3, 2009
Hypothalamic Hamartoma
- A hypothalamic hamartoma is a mass consisting of well-differentiated neurons interspersed with glial cells; it is composed of tissue elements normally found at this site but growing in a disorganized mass.
- It typically presents as a pedunculated or sessile mass, slightly hypo- or isointense to cortex on T1 and generally slightly bright on T2, without contrast enhancement and stable over time. MR spectroscopy shows low NAA, normal to mildly elevated choline and high myoinositol. Generally projects downward but may have upward extension. Small to medium in size but may be giant.
- The classic clinical presentation is that of gelastic seizure (laughing epilepsy), or early onset of puberty. The symptoms often begin in early infancy and are progressive, with general cognitive and/or functional disability.