Erdheim-Chester Disease Presenting as Abdominal Pain

Abstract

Erdheim-Chester Disease (ECD) is an abnormal malignant proliferation of histiocytes that can affect many systems, most commonly the bone. This is a rare disease with few reported cases and is characterized by an infiltration of foamy histiocytes. Although ECD is classified as an orphan disease, those in the field of gastroenterology should be aware of this disorder because of its ability to produce multisystem symptoms, most notably vague abdominal pain with a similar presentation as gastroesophageal reflux disease (GERD). A 63-year-old male with a past medical history of osteoarthritis, GERD, and myocardial infarction (MI) presented with upper abdominal pain for several months duration, worse with palpation. Patient had lower and upper endoscopy revealing only mild gastritis. Abdominal pain was not relieved by a 30-day trial of pantoprazole. Abdominal and pelvic CT showed abnormal thickening around the kidneys, adrenals, and descending aorta (Image 1). This radiographic image displayed a characteristic “hairy kidney” appearance associated with ECD. Further assesment included a follow up bone scan revealing active regions of uptake in the bilateral distal femurs and bilateral distal tibias (Image 1). The retroperitoneal mass was biopsied for evaluation. Histopathologic findings included lymphocytic infiltrate with foamy cytoplasm, irregular nuclei, and rare Touton type giant cells. These cells stained positive for CD68 and negative for S100 (Image 2). This was all consistent with a diagnosis of ECD. Cells were tested for a BRAF V600 E mutation, but results of this test were inconclusive. Because of the mild symptoms the patient was not started on any chemotherapy for his condition. At one year follow up, the patient developed radiating back pain and diabetes insipidus. Despite worsening symptoms, the mass burden appears to be stable. It is estimated that up to 68% of ECD cases occur with renal and retroperitoneal involvement. Therefore, it is possible for a patient with ECD to present to a gastroenterologist complaining of vague abdominal pain. In this case, the patient's abdominal pain was palpable and not relived with PPI treatment, thus warranting further investigation with CT. Catching ECD early is of particular importance because approximately 54% of ECD cases are positive for the BRAF mutation and can be treated with BRAF inhibitors such as vermurafenib.FigureFigure