OR32-1 Endocrine Manifestations of Erdheim-Chester Disease: The Mayo Clinic Experience

Objective: Erdheim- Chester disease (ECD) is a rare form of non-Langerhans cell histiocytosis characterized by multisystem tissue infiltration of foamy histiocytes. Very few studies have investigated the prevalence of endocrine abnormalities in patients with ECD. Based on limited data, it is known that endocrine manifestations are not uncommon. The objective of this study was to characterize the extent of endocrine gland involvement and hormonal function abnormalities in the largest reported endocrine cohort of patients with ECD. Design: Retrospective chart review study of patients with ECD evaluated at the Mayo Clinic from January 1990 to June 2018. A tissue biopsy confirming the diagnosis of ECD was necessary for inclusion in this study. In all cases, the diagnosis of ECD was confirmed using clinical criteria in conjunction with histopathologic findings. Clinical, laboratory, and imaging data were collected. Results: Eighty-three patients with confirmed ECD were included in our study (71.1% women, 83.1% Caucasian, median age at time of diagnosis 55.2[46.3-66.1]). Symptom onset preceded the diagnosis by a median time of 2.7[1.0-6.9] years. Forty-eight patients (57.8%) had at least one hormonal deficiency. Central diabetes insipidus (25.3%) was the most common endocrine manifestation at initial presentation. Fifty percent of patients with central diabetes insipidus had at least one co-existent anterior pituitary deficiency at presentation, most commonly hypogonadism (40%). Among patients that had further endocrine evaluation, 16/64 (25.0%) had primary hypothyroidism and 7/64 (10.9%) had central hypothyroidism. 7/34 (20.3%) had central secondary adrenal insufficiency and 2/34 (5.8%) had primary adrenal insufficiency. Central hypogonadism was found in 18/31 (58.1%) of patients, whereas 6/31 (19.4%) had primary hypogonadism. Growth hormone deficiency was found in 7/59 (29.7%) patients and 4/27 (14.8%) patients had hyperprolactinemia. Imaging revealed involvement of the pituitary/hypothalamus in 18 (21.7%) patients, adrenal glands in 18 (21.7%) patients and testicles in 5 (6.0%) patients. Thirty-five patients (42.2%) had at least one gland involved seen on imaging, Visible gland infiltration did not correlate with hormonal deficiencies. New hormonal deficits appeared during follow-up. Conclusions: This is the largest case series of endocrine manifestations in patients with ECD. Endocrine involvement is frequent in these patients, 57.8% have at least one hormonal deficiency. Because endocrine abnormalities can evolve throughout the course of the disease, patients should have endocrine evaluation periodically.