Case presentation: We report the case of Imad, a 2-year- old Algerian boy referred with a 2-month history of polyuria and polydipsia. Diabetes insipidus was diagnosed by confirming hypernatremia with hyperosmolar serum and inappropriately dilute urine. His polyuria and polydipsia improved dramatically using the oral vasopressin analog. The child had no clinical signs of underlying disease, serum tumor markers were not detected and a skeletal survey suggested no evidence of bone lesions. Magnetic resonance imaging revealed the absence of the posterior pituitary bright spot in T1, consistent with the diagnosis of central DI. A diagnosis of idiopathic central diabetes insipidus was made, and this was well-controlled on oral Desmopressin 120 µg daily The patient was then lost to follow-up until he presented to the neurosurgical department aged 4 years with vomiting, headaches, and blurred vision. CT Scan at admission demonstrated obstructive hydrocephalus and cerebral edema. He underwent an emergency ventriculostomy drain but at this time no diagnosis of the underlying cause was made. He was then admitted to our department aged 6 years suffering from ataxia, dysarthria, and dysmetria. On examination, the patient was short: height 104 cm (< - 2.4 SD), with slowing of height velocity during the previous year, and decrease in weight from 27 kg to 20 kg during in the past 6 months. The boy showed abnormal behavior, ataxia, and dysarthria Anterior pituitary function tests showed complete GH deficiency (<0.1 ng/dl) with no other defect and normal repeat tumor markers MRI demonstrated several large brain lesions and infiltrative changes in the cerebellum. The differential diagnosis included intracranial infection and Acute disseminated encephalomyelitis (ADAM). Biopsy was not performed. Given the clinical history of DI, the neurological picture, compatible imaging findings, and the absence of other systemic signs, the diagnosis of a neurodegenerative form of Langerhans Cell Histiocytosis (LCH) was made. Blood CD1a analysis was negative. The patient received systemic treatment with 12 cycles of intravenous immunoglobulin to prevent disease progression together with GH replacement therapy. Unfortunately, the evolution has not been satisfactory, and his neurological status continues to deteriorate.
Conclusion: We present a case of neurodegenerative LCH which highlights the complex and evolving nature of this rare condition. DI may be the presenting feature of LCH diagnosis and often precedes the eventual diagnosis by several years. Our case illustrates the need for long-term follow-up in children with cranial DI.
15 Sep 2022 - 17 Sep 2022