Diencephalic syndrome: clinical features and imaging findings.

PURPOSE To emphasize the importance of imaging in children with diencephalic syndrome due to hypothalamic/chiasmatic astrocytomas.

METHODS Findings in nine patients (mean age, 26 months) with diencephalic syndrome and hypothalamic/chiasmatic astrocytomas were analyzed retrospectively, including reviewing clinical records, imaging examinations, and follow-up studies.

RESULTS Symptoms and signs included failure to thrive (n = 9), nystagmus (n = 3), visual field defects (n = 1), optic pallor (n = 1), emesis (n = 2), and headache (n = 1). All patients had hypothalamic/chiasmatic masses. Five patients underwent biopsy, and, in all cases, specimens showed low-grade astrocytoma. Imaging studies were available in eight patients. All tumors were large (median maximum diameter, 3.5 cm), involved the chiasm and hypothalamus, and showed homogeneous enhancement. Three patients had hydrocephalus and two had metastases. At follow-up, five patients had recurrent disease and two had died.

CONCLUSION Diencephalic syndrome is a rare cause of failure to thrive in childhood, and diagnosis of a hypothalamic/ chiasmatic astrocytoma might therefore be delayed. The astrocytomas associated with this syndrome are larger, occur at a younger age, and are often more aggressive than other astrocytomas arising in this region.