Document Type

Conference Proceeding

Publication Date

6-2024

Publication Title

Journal of Neuropathology and Experimental Neurology

Abstract

Background: Erdheim-Chester disease (ECD) is a rare clonal histiocytosis neoplastic condition. This condition is characterized by a non-specific infiltration of foamy macrophages in multiple organs, such as the bone or skeletal system (>95%), retroperitoneum, kidneys, and heart, resulting in inappropriate inflammation, fibrosis, and multi-end organ dysfunction. central nervous system (CNS) is present in a minority of cases. This condition is extremely rare with only a few hundred cases reported in medical literature. Methods: We present a case of ECD in a 39-year-old male with past medical history for type-2 diabetes mellitus, neuropathy, and low testosterone on replacement therapy who experienced worsening migraines and was found to have a homogenously enhancing craniocervical mass on brain magnetic resonance imaging (MRI; greatest dimension 3 cm). Mass effect was present with displacement of the inferior brainstem and cervical cord to the right. Clinical differential included primary CNS tumors like meningioma, and surgical resection for definitive diagnosis and management was pursued. Intraoperatively, it was very fibrous and difficult to resect. It encased the vertebral artery and so only a limited resection could be performed. Results: Grossly the mass appeared orange-yellow to pale-tan with a soft texture. Microscopically numerous histiocytes with ranging degrees of foamy cytoplasm in a background of increased fibrosis was identified. Histiocytic markers such as CD163 and PU.1 were diffusely positive in these cells, while CD1a and Langerin were both negative. No microorganisms were identified on special stains either. The patient was found to be BRAF mutant positive, supporting a diagnosis of ECD. Abdominal imaging and a biopsy of a renal mass was also consistent with ECD. The patient was appropriately started on Vemurafenib. Conclusions: This case highlights the importance of considering ECD when histiocytosis is identified.

Volume

83

Issue

6

First Page

530

Comments

American Association of Neuropathologists 100th Annual Meeting, June 6-9, 2024, Olympic Valley, CA

Last Page

531

DOI

10.1093/jnen/nlae036

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