Fact-sheet: Hypothalamic hamartoma
- Tuber cinereum hamartoma
- Diencephalic hamartoma
Updated on 04/20/2018 at 5:57 PM
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Definition
Hamartoma: normal nervous tissue (gray matter) located in an ectopic position.
Hypothalamic hamartoma = Diencephalic hamartoma = Diencephalic hamartoma
Typical location: interpeduncular cistern (tuber cinereum), posterior to the optic chiasm and pituitary stalk and anterior to the basilar trunk
2 types:
- parahypothalamic hamartoma
- intrahypothalamic hamartoma
Course: stable, non-progressive lesion
Clinical features
Children ++
- precocious puberty
- Epilepsy: gelastic seizures (unmotivated laughter), other seizure types possible
- cognitive and neuropsychiatric disturbances sometimes associated
The type of symptomatology observed depends on the location and/or extent of the hamartoma:
- large, sessile lesion: seizures
- small, pedunculated lesion: precocious puberty
A combination of both types of symptomatology is sometimes observed.
Radiography
Occasionally suprasellar calcifications, erosion of the sella turcica
CT
Homogeneous, isodense (or slightly hypodense) suprasellar mass.
Occasionally cysts and calcifications (rare)
MRI
Oval mass, a few millimeters to a few centimeters in size, sessile or pedunculated, well-defined
Signal identical to that of parenchyma (gray matter), occasionally slightly hyperintense on T2.
Large lesions may be heterogeneous and contain cysts.
No enhancement after contrast administration.
Spectroscopy:
- Decreased NAA and increased choline: decreased neuronal density and gliosis
- Increased mI (myoinositol)/Cr (creatine): increased glial component and T2 hyperintense lesion
Management
Follow-up.
Hormonal medical treatment.
Anti-epileptic treatment.
Lesion size should remain stable; if it increases, surgery/biopsy may be indicated.
Differential diagnosis
- Hypothalamic glioma (astrocytoma): T2 hyperintensity and enhancement after contrast administration
- Craniopharyngioma
- Ectopic posterior pituitary
- Lipoma
- Germinoma
- Langerhans cell histiocytosis
