[Evaluation of six cases with hypothalamic hamartoma: the relationship between MRI findings and clinical features]

We evaluated the relationship between MRI findings and clinical features in patients with hypothalamic hamartoma (HH).

We retrospectively reviewed MRI and clinical data (mental retardation, precocious puberty, behavioral problems, and epilepsy) in six patients (3 males and 3 females, ages 12 to 26) with HH. Based on the MRI classification by Arita, HH was classified into two types: parahypothalamic (P) and intrahypothalamic (I).

Only one patient was classified as having P-type HH and five were classified as having I-type HH. The patient with P-type HH (diameter 21 mm) showed precocious puberty and mild behavioral problems, but did not developed epilepsy. On the other hand, all patients with I-type HH (diameter 10-32 mm, median 17 mm) developed epilepsy and behavioral problems. Except for one patient, who had the smallest sized HH, I-type four patients developed mental retardation and precocious puberty. Among patients with I-type HH, the size of the tumor was inversely correlated with the age at epilepsy onset and with the degree of mental retardation (DQ/IQ).

Our data suggested that the MRI classification by Arita, when combined with tumor size, might be helpful in predicting the clinical manifestations in patients with HH.