Endocrine Abstracts

Langerhans Cell Histiocytosis (LCH) is a neoplastic histiocytic disorder that is rare in adults. LCH can present as a single or multi-site disease (mostly bone/skin). The most frequent endocrine abnormality associated with LCH is Arginine Vasopressin Deficiency (AVP-D), followed by growth hormone and gonadotropin deficiency. We present the case of a 34-year-old female with complex, sequential multi-system involvement. She had a background history of untreated Graves’ disease. She initially presented to the emergency department with a spontaneous pneumothorax, and jaundice due to severe liver dysfunction. The pneumothorax was managed with a chest drain, and later video assisted thoracoscopic surgery (VATS) pleurodesis. Further imaging revealed hepatic cystic lesions, hepatosplenomegaly, severe cystic lung disease and a diffusely enlarged thyroid causing narrowing of the trachea and jugular veins. Following urgent thyroid surgery, histology from the thyroid gland showed infiltrates consistent with LCH. Subsequent to the thyroidectomy, the patient developed hypotonic polyuria, severe polydipsia, and subclinical thyrotoxicosis. Daily fluid intake was up to 6.5L with output reaching 9.5L. Desmopressin was commenced for AVP-D, with good response. MRI pituitary showed thickening and enhancement of infundibulum which although nonspecific, is supportive of LCH. Biochemical pituitary testing showed suppressed gonadotropins, low Insulin-like Growth Factor 1, subclinical hyperthyroidism and normal morning cortisol. Treatment with Cladribine and Prednisolone was initiated. Desmopressin dose and fluid balance required regular adjustment during the chemotherapy treatment. She continued to have significant complications including surgical emphysema, dysphagia, and persistent bilateral pneumothoraces. LCH should be considered in the differential diagnosis of AVP-D associated with pituitary stalk thickness. Multi-disciplinary care involving endocrinology is an essential part of care for LCH patients.