Background: Insipidus diabetes is a rare disease in pediatric endocrinology.
Objective and hypotheses: Facing a thickened pituitary stalk on MRI pituitary, the main diagnosis to mention are: dysgerminoma, histiocytosis, sarcoidosis, and autoimmune hypophysitis. Histiocytosis is a rare and often underdiagnosed cause.
Method: We report the case of a teenage girl who presented polyuriapolydipsia syndrome at the age of 14 years consequent full central insipidus diabetes confirmed by water restriction test.
Results: MRI showed pituitary stalk thickened measured at 2.9 mm with a loss signal of post-pituitary. The initial analysis were negative (blood and cerebrospinal fluid markers of dysgerminoma, body skeletal radiographies, bone scintigraphy, ear scan, lung scan, and auto-immune research). The patient was treated with desmopressin. Later, the pituitary stalk has grown to 5 mm with apparition of an asthenia, a weight gain, and several anterior pituitary deficits in gonadal and somatotropic axis. The GHD could not be supplemented until the diagnosis of dysgerminoma had not been dismissed. A stalk biopsy was performed at the age of 15.5 showing nonspecific inflammatory tissue and CD1a+ marker for a histiocytosis X. Complementary analysis showed bone defects and lung nodules which were not present during the initial radiographies.
Conclusion: Histiocytosis X is a difficult and late diagnosis. Annual repetitions skeletal radiographies in search of bones lesion, skin biopsy and repeat pituitary MRI before placing the indication of tige biopsy must be part of the key elements of diagnosis.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology