ESPE Abstracts

Introduction: The annual incidence of Langerhans cell histiocytosis (LCH) is 5 per million in admission with a diagnosis of isolated central diabetes insipidus (CDI) in children under the age of 15. Here, the process leading to the diagnosis of LCH at presentation with isolated CDI, imaging findings, and the sellar erosion, which has not been previously reported in the literature, will be discussed.

Case presentation: A 4-year-5-month-old male patient was referred to our outpatient clinic with complaints of drinking too much water and urinating frequently for 2 months. Physical examination, complete blood count, and biochemical tests were normal. Water deprivation test was performed with a prediagnosis of diabetes insipidus in a patient with a urine density of 1001. After water deprivation test, the patient was diagnosed with diabetes insipidus with serum osmolarity 303 mOsm/L and urine osmolarity as 121 mOsm/L. Urinary osmolarity increased by 330% after administration of 10 microgram of desmopressin acetate nasal spray solution. With these findings, the patient was diagnosed with CDI and desmopressin treatment was initiated. Other pituitary functions were found to be normal. In the follow-up of the patient, it was observed that his body temperature rised to 38-38.4°C in the evening once a day, and fell spontaneously and did not persist. On physical examination, any focus to explain the fever was not found. In laboratory tests, increases in acute phase reactants (WBC: 14.89x10⁹/L, CRP: 76.8 mg/l, Sedimentation: 70 mm/hour) and anemia (Hb: 10 g/dL, MCV: 66.5 fL, RDW: 16.3%) were observed. A lytic expansile bone lesion in the mid-diaphyseal part of the left-clavicle was found on skeletal survey. On pituitary imaging, it was observed that the height of the pituitary anterior gland was slightly increased. The infundibulum was significantly thick and the bright signal of the neurohypophysis was not observed. On cranial MRI, widespread lytic-destructive bone lesions were observed in the bone structure forming the sella turcica, and the lateral wall of the left orbital. The patient, who had a pre-diagnosis of LCH, was directed to an external center for bone biopsy and it was learned that the treatment for the diagnosis of LCH was planned.

Conclusion: Presence of isolated CDI with low-grade intermittent fever should be a warning for the diagnosis of LHH. But the patients with CDI should be evaluated in terms of LHH, the most known underlying cause, regardless of the presence of fever.