A rare case of erdheim-chester disease with braf mutation – a case report

Abstract

Erdheim-Chester disease (ECD) is a rare histiocytic neoplasm with multisystemic involvement, commonly involving the bones, cardiovascular organs and retroperitoneal region. We report a 68-year-old female who was admitted due to a fall following an episode of dizziness, and was noted to have a retroperitoneal soft tissue mass involving the bilateral perinephric spaces and bowel mesentery, which extended superiorly into the thoracic cavity, causing encasement of the ureters, adrenal glands and major vessels. A biopsy revealed a histiocytic infiltrate with foamy cytoplasm, which was positive for CD163, fascin and factor XIIIa on immunohistochemical staining, but was negative for CD1a, S100, AE1/3 and HMB45. Molecular testing for BRAF was positive. The overall clinical, imaging and histology findings were supportive of a diagnosis of ECD. Awareness of this entity and exclusion of its differential diagnoses is important to ensure correct diagnosis for subsequent targeted therapy. 1.Brousse N, Pileri SA, Haroche J, et al. Erdheim Chester disease. In: Swerdlow SH, Campo E, Harris NL, et al. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissue. Revised 4th ed. Lyon: IARC, 2017; 481–2.2.Goyal G, Heaney ML, Collin M, et al. Erdheim-Chester disease: consensus recommendations for evaluation, diagnosis, and treatment in the molecular era. Blood 2020; 135: 1929–45.3.Aubart FC, Emile JF, Carrat F, et al. Targeted therapies in 54 patients with Erdheim-Chester disease, including follow-up after interruption (the LOVE study). Blood 2017; 130: 1377–80.