Endocrine Abstracts

Introduction: Langerhans cell histiocytosis (LCH) is a systemic disorder characterized by clonal proliferation of immature dendritic cells observed mainly in children. The affection of the sellar region in adults with central diabetes insipidus as the first manifestation of the disease is extremely rare creating a problem of etiological diagnosis especially when central diabetes insipidus (CDI) is apparently isolated.

Case description: A 21-year-old man was referred for evaluation of recent polyuria and polydipsia with a history of headache for the past 03 years. Initial biochemistry and hormonal evaluation were normal. Magnetic resonance imaging(MRI) of the brain showed a loss of spontaneous T1 hyperintensity of the posterior pituitary, a globular anterior hypophysis and a thickened pituitary stalk measured at 07 mm, filling the opto-chiasmatic cistern and exerting a mass effect on the optic chiasma In addition, the patient had a type II Chiari malformation with intramedullary cyst and a malformation of the colobomatous eyeballs. Notably, The MRI showed a non-expansive osteolytic lesion of the frontal bone. Additional investigations were performed in order to establish etiological diagnosis but were non contributory. A bone biopsy of the frontal bone was then performed, and the pathologic examination concluded to LCH diagnosis. Desmopressin therapy was therefore initiated. The patient was referred to the hematology department where he received chemotherapy (vinblastine, Etoposide) with corticosteroid therapy

During follow-up: the patient developed GH deficiency, TSH deficiency, and FSH and LH deficiencies, corticotropic axis has not been evaluated because the patient was on corticosteroid therapy. There was no reduction of desmopressin doses. The frontal lesion was not present on the follow-up MRI. On the other hand, it showed a new lesion in the left frontal sinus suggesting an osteoma; a CT scan remains necessary for a better evaluation of the bony structures

Conclusion: In this patient LCH was revealed by central diabetes insipidus as the first manifestation, associated with solitary bone lesion. Treatment included desmopressin replacement and chemotherapy. During follow-up, the patient developed a panhypopituitarism with no improvement in diabetes insipidus with the appearance of a second bone lesion in the left frontal sinus