Delayed presentation of diencephalic syndrome associated with leptomeningeal dissemination in a child.

To cite: Crawford JR, Shayan K, Levy ML. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2013010265 DESCRIPTION A 7-year-old girl presented to our hospital with a history of failure to thrive since 1 year of age. Her prior workup included negative serum and stool studies to exclude gastrointestinal, metabolic and endocrinological causes. She has mild speech delay, but otherwise had achieved all her developmental milestones. On admission, she was extremely cachectic weighing 11 kg (<1st percentile) and a head circumference of 49 cm (5th percentile). Neurological examination was significant for bilateral papilloedema, optic nerve pallor and peripheral visual field deficits. MRI of the brain revealed a large contrast-enhancing suprasellar tumour with significant hydrocephalus (figure 1A). Areas of leptomeningeal enhancement along the dorsal brainstem prompted spinal MRI that showed diffuse leptomeningeal metastatic disease (figure 1). The patient underwent near total resection of the suprasellar mass where pathology was consistent with a juvenile pilocytic astrocytoma with pilomyxoid features (figure 2). Postoperatively, she exhibited signs of hypothalamic dysfunction including hypothermia, hypotension, bradycardia, diabetes insipidus and near complete visual loss. Diencephalic syndrome was first recognised in 1951 as a constellation of severe emaciation and preserved linear growth velocity in children associated with hypothalamic tumours. Treatment of hypothalamic–chiasmatic tumours with chemotherapy may result in weight gain that correlates with tumour shrinkage in some cases. Leptomeningeal metastatic disease has been reported in children with low-grade suprasellar astrocytomas, and