Nervous System Disorders
rare tumor
- sporadic
- associated with tuberous sclerosis; may degenerate into giant cell astrocytoma
Age: 0–30 years
Location: temporal lobe, hamartoma of tuber cinereum, subependymal in tuberous sclerosis
- cyst with little mass effect, possibly with focal calcifications
- usually NO enhancement
Hypothalamic hamartoma
= HAMARTOMA OF TUBER CINEREUM
= rare developmental congenital malformation composed of normal neuronal tissue arising from posterior hypothalamus in region of tuber cinereum
Age: 1st–2nd decade; M >F
Histo: heterotopic collection of neurons, astrocytes, oligodendroglial cells (closely resembling histologic pattern of tuber cinereum)
- neurodevelopmental delay
- central precocious puberty, gelastic seizures
Location: mamillary bodies / tuber cinereum, hypothalamus
- parahypothalamic hamartoma (common)
- isosexual precocious puberty ← LHRH secretion
- pedunculated mass attached to tuber cinereum / mamillary bodies by thin stalk
- intrahypothalamic hamartoma (rare)
- gelastic seizures, hyperactivity
- sessile mass with broad attachment to hypothalamus
- distortion of 3rd ventricle
Size: up to 4 cm in diameter
- well-defined round / oval mass projecting from base of brain into suprasellar / interpeduncular cistern
- stable in size over time
CT:
- round homogeneous mass isodense with brain tissue
- NO enhancement
MR:
- well-defined round pedunculated mass suspended from tuber cinereum / mamillary bodies
- imaging characteristics of gray matter:
- iso- to mildly hypointense on T1WI
- iso- to slightly hyperintense on T2WI
- NO gadolinium enhancement