(CSEMP020) ENDOCRINE MANIFESTATIONS OF ERDHEIM-CHESTER DISEASE: A CASE SERIES

Abstract:

Introduction: Erdheim-Chester Disease (ECD) is a non-Langerhans Cell Histiocytosis commonly associated with the BRAFV600 mutation. Approximately 800 cases have been reported in literature. Common endocrine manifestations include pituitary involvement in 70% of patients, and central diabetes insipidus (CDI) in up to 50% of patients. We present two patients with ECD and endocrine-related manifestations.

Case Presentation: Patient #1 is a 75-year-old male, who initially presented with shortness of breath secondary to bilateral pleural plaques. Subsequent pleural biopsy revealed histiocytes. Initial workup demonstrated primary hypogonadism with a low total testosterone of < 0.4 (8.4 - 28.8) and a cortisol level of 283. Subsequent pituitary panel was unremarkable other than an elevated FSH (52.1) and LH (24.7). PET scan showed moderate uptake in adrenal glands bilaterally, without symptoms of adrenal insufficiency. PET and CT scans also revealed soft tissue thickening of the abdominal aorta and perirenal spaces bilaterally, classic radiologic features of ECD. In contrast, patient #2 is a 71-year-old female with a longstanding history of polyuria and polydipsia. She was diagnosed with CDI following an overnight 10-hour water deprivation test that showed a high morning sodium of 149, serum osmolality of 306, and a dilute urine osmolality of 111. She improved clinically and biochemically with desmopressin. MRI sella showed hypophysitis and bilateral masses near the medulla, encasing the right vertebral artery, and CT scan of the abdomen showed circumferential thickening of the abdominal aorta and proximal common iliac arteries. Bone scan revealed infiltration of vertebrae and long bones, with subsequent biopsy of the distal femur demonstrating foamy histiocytes confirming the diagnosis.

MANAGEMENT AND OUTCOME: Patient #1 was managed by endocrinology, hematology, and urology. Regarding his primary hypogonadism, testosterone gel was initiated, and total testosterone improved to 9.6 (6.0-34.0). Repeat AM cortisol was 263 and he will be considered for an ACTH stimulation test. He was also started on trametinib with clinical improvement in symptoms. Patient #2 was started on oral desmopressin with clinical improvement. She is awaiting hematology consult for initiation of immunosuppressive agents and genetic testing. In follow-up, serial adrenal and pituitary scans in addition to hormone panels are important to monitor for new endocrine pathology.