A new case study details a 65-year-old patient diagnosed with Erdheim-Chester disease (ECD), a rare histiocytic neoplasm that uncommonly presented with gastroenterological manifestations.

The clinical presentations of ECD vary. While some patients are asymptomatic and the condition is incidentally detected via imaging, others experience multiorgan dysfunction and a rapidly progressive disease.

The condition was first described in 1930 and since then, fewer than 1000 cases have been reported worldwide, researchers explained. Although ECD typically affects the skeletal system, over half of patients also have extraskeletal involvement. It has no known cure and prognosis varies based on treatment response and disease site.

Upon first presentation, the current patient had hematuria and abdominal pain. The male patient underwent a computed tomography scan that revealed a retroperitoneal mass. He also experienced night sweats, nausea, and intermittent non-bloody diarrhea.

Medical history queries revealed coronary artery disease with previous myocardial infarction, impaired fasting glucose, and hypertension. “A CT-guided biopsy of the mass showed dense fibroadipose tissue with predominant lymphocytes and plasma cells,” authors wrote.

After being seen by an oncologist and undergoing a nondiagnostic bone marrow biopsy, the patient was referred to the current gastroenterology clinic for evaluation of his unexplained weight loss, nausea and other symptoms.

Images carried out at the center revealed “retroperitoneal fibrosis surrounding both kidneys, renal vessels, left ureter, proximal right ureter, portions of the aorta, common iliac arteries, and the left internal and external iliac arteries without any evidence of vascular obstruction or hydronephrosis.”

The patient then underwent a laparoscopic retroperitoneal biopsy, which showed “fibroadipose tissue involved by a subtle histiocytic infiltrate in a background of marked fibrosis, scattered lymphocytes, and plasma cells,” authors wrote.

Following the detection of the BRAF V600E mutation within the histiocytes, the patient was diagnosed with ECD.

Most patients with ECD are diagnosed within the fourth and seventh decade of life, and most cases occur in males. Clinical manifestations of ECD include diabetes insipidus, mediastinal infiltration, orbital masses, and cardiac involvement. However, “involvement of liver, pancreas, and gastrointestinal tract is extremely rare,” authors said. Gastrointestinal symptoms, though uncommon, can include vomiting, abdominal pain and nausea.

Because the current patient had such a nonspecific presentation, authors noted there was a broad range of differential diagnoses for retroperitoneal masses, including neoplastic retroperitoneal masses like lymphoma. It could have also been liposarcoma, leiomyosarcoma, neurogenic tumors, or germ-cell tumors or even benign etiologies like precious radiation therapy or IgG4-related disease (IgG4-RD).

Thanks to the retroperitoneal involvement and tissue IgG4 staining, IgG4-RD was initially considered, though this condition is typically associated with a raised serum IgG4, which was absent in the patient.

Treatment is recommended for all symptomatic patients with ECD, researchers wrote, and targeted therapy is the preferred modality.

“Vemurafenib selectively inhibits the kinase domain of mutant BRAF and is used as first-line therapy for individuals with BRAF V600E ECD. MEK inhibitors may be considered for ECD patients without BRAF V600E,” they said.

The patient was started on vemurafenib. A positron emission tomography scan was carried out three months later and showed radiologic improvement. On his subsequent follow-up he was diagnosed with concomitant chronic myelomonocytic leukemia, was initiated on cobimetinib, and has been doing well for 2 years.

“Although uncommon, physicians should consider the possibility of ECD when evaluating patients who have persistent unexplained gastrointestinal complaints and retroperitoneal perinephric mass-like infiltration on cross-sectional imaging,” authors concluded.

Reference

Chatterjee A, de la Fuente J, Rech K, Takahashi N, and Majumder S. A rare case of abdominal pain: Edrheim-chester disease. ACG Case Rep J. Published online June 2023. doi:10.14309/crj.0000000000001049