Abnormal Pituitary Imaging and Associated Endocrine Dysfunctions in Erdheim-Chester Disease

Background: Erdheim Chester disease (ECD) is a rare histiocytic neoplasm associated with hypothalamic and pituitary infiltration and dysfunction. We determined the abnormal pituitary imaging (API) phenotypes in subjects with ECD and analyzed their associated endocrine dysfunctions. Methods: This was a cross-sectional examination of a natural history cohort study of 61 subjects with ECD performed at a tertiary care clinical research center. The diagnosis of ECD was based on clinical, molecular, and histopathological features. Enrolled subjects underwent baseline endocrine tests of anterior and posterior pituitary function in addition to pituitary imaging. The following variables were analyzed- age, sex, body mass index (BMI), BRAF V600E, hsCRP, ESR, pituitary hormone deficit number, diabetes insipidus (DI), and panhypopituitarism. Fisher’s exact test or t-test/Wilcoxon tests compared patients with and without API. Results: Sixty-one subjects with ECD (age ±SD: 54.3 ±10.9, 46 (75.4%) males) were studied. The prevalence of API was 32.8% (n=20), who were younger than those with normal imaging (50.3 ±10.5 vs 56.3 ±10.7 yrs, p=0.042). The most common pituitary imaging abnormalities included thickened pituitary stalk (18.03%, n=11/61), followed by pituitary encasement, small pituitary and abnormal morphology (6.55%, n= 4/61 for each). A higher prevalence of DI (45.0% vs 9.8%, p=0.003) and panhypopituitarism (45.0% vs 4.9%, p<0.001), and a higher number of pituitary deficits (median (IQR): 2.0 (0-2.5) vs 0 (0-1.0), p=0.007) were noted in patients with API compared to those with normal imaging. Other biochemical markers were similar between both groups. Conclusion: Abnormal pituitary imaging was commonly seen in ECD and was also associated with a younger age and hormone deficits suggesting associations with pituitary structure-function.