Urologic Manifestations of Erdheim-Chester Disease.

Objective: To describe the urologic manifestations of Erdheim-Chester disease (ECD). ECD is a rare multisystem disorder of non-Langerhans cell histiocytosis. In addition to classic long bone involvement, the retroperitoneum is a well-established site of disease infiltration. Herein, we present the urologic manifestations and outcomes of ECD in a large series of patients. Methods: We identified 47 patients diagnosed with ECD between 1996 and 2012 at our institution. The medical records and imaging for these patients were reviewed for urologic involvement, including perirenal soft tissue encasement, renal atrophy, hydronephrosis, chronic renal insufficiency, diabetes insipidus, and lower urinary tract symptoms. Results: At diagnosis, the median patient age was 57 years (interquartile range 49, 68), and median follow-up after diagnosis was 3 years (interquartile range 1.8, 7.3). There were 31 male patients (66%) and 16 female patients (34%). The majority of these patients (37, 79%) demonstrated evidence of urologic involvement from ECD, requiring urologic surgery in 13 (28%). This urologic involvement included retroperitoneal infiltration (28, 60%), worsening lower tract urinary symptoms from diabetes insipidus (21, 45%), hydronephrosis (10, 21%), and chronic kidney disease (18, 38%). Conclusion: The incidence of urologic involvement with ECD is higher than previously reported in the published data. Urologists should be aware of this disorder, as it might mimic other retroperitoneal diseases and might contribute to lower urinary tract symptoms, hydronephrosis, renal atrophy, and chronic kidney disease. [ABSTRACT FROM AUTHOR]