PITUITARY-STALK THICKENING WITH DIABETES-INSIPIDUS PRECEDING TYPICAL MANIFESTATIONS OF LANGERHANS CELL HISTIOCYTOSIS IN CHILDREN

In up to 25% of cases of children with central diabetes insipidus no o rganic cause can be documented. We present three boys (age 2.2, 2.3 an d 6 years at diagnosis) with acute onset central diabetes insipidus, i n whom the only pathological finding using MRI was a thickened central part of the pituitary stalk (> 2.5 mm). Recent reports demonstrate si milar MRI findings in adults with Langerhans cell histiocytosis (LCH), sarcoidosis, or tuberculosis, and in children with proven LCH and dia betes insipidus. In those adults with LCH, the pituitary stalk lesion has been histologically verified as a sequela of LCH. In contrast, in two of our three patients pituitary stalk thickening preceded the typi cal peripheral lesions of LCH by several months, whereas in the third patient there is as yet no evidence of systemic disease. We conclude t hat thickening of the central part of the pituitary stalk might repres ent the first manifestations of LCH clinically presenting with diabete s insipidus. MRI investigation of the pituitary stalk in children with unexplained central diabetes insipidus and accurate follow up in pati ents with thickening of the pituitary stalk in necessary to avoid miss ing other manifestations of a systemic disease.