Endocrine Abstracts

Introduction: Langerhans cell histiocytosis (LCH) is a rare disease characterized by non-specific granulomatous deposits in many tissues. The hypothalamic-pituitary region is infiltrated in 5 to 50% of patients with LCH but most often in those with the multifocal form. Diabetes insipidus (DI), the most common hormonal abnormality, occurs in 15–50% of patients. Anterior pituitary deficiency occurs only in 5 to 20% of patients. We report the case of a patient with LCH who has dissociated anterior pituitary deficiency.

Observation: A one-year old male patient was admitted for polyuropolydypsic syndrome with a long-term fever. The water restriction test was positive with a positive response to Desmopressin. The diagnosis of central DI was therefore retained. Pituitary MRI showed thickening of the pituitary stalk. In addition, the child had hepatosplenomegaly and rash on clinical examination, cytolysis with hepatic cholestasis, and bicytopenia on biology. The liver biopsy showed showed sclerosing cholangitis with presence of histiocytic cells and PS 100 positive. The diagnosis of LCH in its multi-systemic form was therefore retained. The patient received a chemotherapy regimen and Desmopressin substitution. The evolution was marked by an improvement in hepatic and hematologic manifestations but the patient exhibited a break in the growth curve during monitoring with persistent hyponatremia despite the dose adjustment of Desmopressin. The hormonal assessment showed a collapsed IGF1 level, a low cortisolemia and a low ACTH. The diagnosis of a somatotropic and corticotropic deficiency was therefore retained and the patient was put on hormone replacement therapy.

Discussion: ACTH deficiency is usually present in panhypopituitarism and rarely as an isolated deficiency. The incidence of ACTH deficiency in patients with LCH ranges from 30% to 50%. GH deficiency may precede the onset of all other endocrine deficiencies or may occur after radiotherapy treatment. Gonadotropin deficiency was the second most common pituitary hormone deficiency. A moderate disconnection hyperprolactinemia can be seen. Thyroid status is usually normal.

Conclusion: Anterior pituitary deficiency should be considered in all patients with LCH who require therefore close follow-up and appropriate substitution treatment.