Bilateral Adult Epibulbar Xanthogranulomas Suspicious for Erdheim-Chester Disease

Purpose: The aim of this study was to report the clinical, imaging, and histopathological findings of bilateral, conjunctival adult-onset xanthogranulomas that raised the prospect of a mild form of Erdheim-Chester disease. Methods: This is a case report. Results: A 35-year-old white male complaining of ocular irritation, presented with bilateral, nasal and temporal, yellow, elevated conjunctival lumps first noticed 1.5 years back, which were not associated with other ocular findings. The lesions were firm, attached to the underlying episclera, and measured 1.1 x 0.9, 1.1 x 0.8, 1.2 x 0.5, and 0.5 x 0.5 cm in the temporal and nasal right and left eyes, respectively. Each mass was fleshy with vascularity at the peripheral margin. Histopathologic evaluation after excisional biopsy revealed lipidized xanthoma cells, multiple Touton giant cells, and lymphocytes. Immunohistochemical staining was positive for adipophilin (lipid), CD68(+), CD163(+) histiocytes, CD3(+) T cells (with CD8(+) cytotoxic T cells > CD4(+) T-helper cells), and virtually no CD20(+) B cells or IgG4(+) plasma cells. The patient later acquired similar xanthogranulomatous subcutaneous lesions on the extremities. Positron emission tomography scans showed sclerosis in the medullary cavities of the tibia and the radius of both legs and arms, and an absence of retroperitoneal lesions. A normal serum immunoelectrophoresis and the absence of a BRAF gene mutation were demonstrated. Conclusions: Adult-onset xanthogranuloma can present as a solitary conjunctival mass without periocular or orbital involvement. The clinical, histopathologic, and radiologic findings in this case are suggestive of Erdheim-Chester disease without displaying any life-threatening lesions to date. Histopathologic and imaging studies can help in obtaining a diagnosis. Ophthalmologists should be aware that xanthogranulomatous conditions may have potential systemic implications, and a thorough systemic evaluation is recommended for lesions that initially seemed to be isolated in nature.