Endocrine Abstracts

Introduction: Langerhans cell histiocytosis (LCH) is a rare systemic disease. Diabetes insipidus is the most frequent endocrine alteration and occurs mostly after diagnosis. Others are hypogonadism, growth hormone deficiency (GHD) and alterations in glucose metabolism.

Clinical case: A 61-year-old smoker, diagnosed with LCH 9 years ago with pulmonary and hepatic involvement, without treatment, who consulted for asthenia, unquantifiable polyuria, polydipsia and 3 kg of weight loss over a period of 2 weeks. The physical examination showed blood pressure of 128/81 mmHg and dry mucus membranes. The blood test showed hypernatremia, hyperchloraemia, hyperglycemia and elevated glycosylated hemoglobin (HbA1c). It was oriented as type 2 diabetes mellitus (DM2) and treatment with metformin was initiated. The patient did not show improvement and because of the persistence of the same symptoms he went to the emergency department. The blood test showed hypernatremia with high osmolality, hyperglycemia, hypercalcemia and elevated HbA1c. The 24-hour urine test was 10 litres and had decreased osmolality and density. Given these findings, Diabetes insipidus was also diagnosed with DM2. A pituitary magnetic resonance was requested that revealed thickening of the pituitary stalk and absence of posterior pituitary bright spot in the T1 sequence. Treatment was started with sublingual desmopressin with normalization of serum sodium and diuresis. The pituitary hormones were normal, except for an elevation of cortisol and ACTH and a decreased vasopressin. Cortisol after 1 mg dexamethasone suppression test was normal. Positron emission tomography (PET) showed hypermetabolism only in the pituitary gland. The patient was discharged with sublingual desmopressin 60 mcg every 8 hours and metformin 850 mg every 12 hours.

Conclusions: - We have to consider the endocrinological alterations in patients diagnosed with LCH and their referral to Endocrinology consultations

- The importance of quantifying polyuria and assessing the coexistence of two types of diabetes in these patients, as in our case