Giant hypothalamic hamartoma: case report and literature review

Hypothalamic hamartomas are very rare (1:200,000) and range in size from 17.9 to 18 mm. When their dimensions exceed 30-40 mm, they are classified as giant hypothalamic hamartomas. We present a 14-month-old boy with central precocious puberty and gelastic seizures in whom a magnetic resonance imaging scan revealed a giant hypothalamic hamartoma measuring 50 x 50 x 40 mm. In the 11 cases described so far, we found that in comparison to the average-size lesion, giant hypothalamic hamartomas had a lower frequency of precocious puberty, but a similar frequency of seizures. The mean age at diagnosis was younger, and males were more affected than females. Magnetic resonance imaging results were similar with the exception of mass effect. Giant hypothalamic hamartomas had a higher tendency to adhere to surrounding structures. Their invasiveness and cystic degeneration were frequent findings among the 11 studies. Surgical removal was ineffective in controlling refractory epilepsy and caused postoperative morbidity in all patients.