Endocrine Abstracts

Introduction: Central diabetes insipidus reflects a serious underlying pathology in children. The etiologies are dominated in pediatric population by: central nervous system (CNS) tumors and malformations, histiocytosis, postoperative, radiation, and trauma injury to the hypothalamic-pituitary region. We report in this work three observations illustrating rare etiologies of pediatric central diabetes insipidus in the endocrinology-diabetology and nutrition department of the Mohammed VI University Hospital Center of Oujda in the eastern of Morocco.

Observations:

Observation n°1: A 17-year-old female patient, with a history of influenza-like illness on probable COVID19 infection, admitted for exploration of a polyuria-polydipsia syndrome associated with headaches and significant decrease in visual acuity. An MRI of the hypothalamic-pituitary region has shown a hyperintense aspect of the pituitary gland on the T2 sequence with exaggerated enhancement of the gland after injection, pituitary height measured at 8 mm suggesting hypophysitis. The diagnosis was supported by the clear improvement both visually and diabetes insipidus after corticosteroid therapy.

Observation n°2 : A 15-year-old female patient consulted for a polyura-polydipsia syndrome associated with headaches. An MRI of the hypothalamic-pituitary region has been realized showing an intra- and supra-sellar tumor process, with irregular contours, T1 isosignal, T2 hypersignal, heterogeneously enhancing and delimiting several cystic areas. A transphenoidal surgery was performed and the anatomopathological study came back in favor of a pituitary tuberculosis. The sputum testing for tuberculosis and quantiferon assay were negative, but the tuberculin skin testing was positive. The patient received anti-bacillary treatment with good evolution.

Observation n°3 : A 15-year-old child with no notable pathological history was admitted for a polyura-polydipsia syndrome and secondary enuresis associated with frontal headaches. Biological explorations confirmed the central origin of diabetes insipidus. An MRI of the hypothalamic-pituitary region was performed showing a sellar mass in spontaneous T1 hypersignal, with a heterogeneous signal in T2, not enhancing after injection of Gadolinium, with a mass effect on the posterior pituitary, evoking a Rathke’s cleft cyst in apoplexy.

Discussion-Conclusion: These three cases reflect the complexity of the diagnosis and the etiological polymorphism of central diabetes insipidus in children, making its management more delicate. Hence the interest of a meticulous etiological investigation in which hypothalamic-pituitary MRI plays an essential role, in the hypothesis of a tumoral lesion of this anatomical region.