Abstract
Background: Juvenile xanthogranuloma (JXG) is the most common form of non-Langerhans cell histiocytosis. The cutaneous form of the disease spontaneously regresses over several years, while systemic forms of JXG require specific therapy and can be life-threatening for patients.
Case Presentation: A 6-year-old girl, born prematurely, was admitted to the newborn intensive care unit after birth due to hypoxia, hydrocephalus, and failure to thrive (low birth weight, not talking, and not walking). She also had a family history of dysmorphism and global developmental delay. The patient presented with multiple papular orange-colored lesions on her left elbow and right hand. On examination, she was active, non-syndromic, and pink in color, with a good pulse volume and no signs of cleft lip or palate. There were multiple diffuse yellow swellings around the left elbow and right hand, with lesion sizes ranging from 0.5 to 4.0 cm. A skin biopsy from the lesions on her left elbow showed dense skin infiltration by sheets of mononuclear histiocytic cells. These cells were polygonal, spindle-shaped, plump, and had abundant pale eosinophilic cytoplasm with indistinct borders. Mitosis was rare, and scattered foam cells were present, especially in the superficial dermis. There was no necrosis. The lesion cells were diffusely positive for CD68 and negative for CD1a and S100, findings consistent with JXG.
Conclusion: JXG is a rare benign histiocytic disorder that primarily affects infants and young children. It is characterized by yellowish nodules or plaques on the skin, which are usually self-limiting.

Key words: Juvenile xanthogranuloma, congenital, non-Langerhans cell histiocytosis, case report, Saudi Arabia