Juvenile Xanthogranuloma Mimicking Other Dermal Nodules: A Diagnostic Challenge in an Infant.

Juvenile xanthogranuloma (JXG) is a benign histiocytic proliferation that typically presents as solitary or multiple skin lesions in infants and young children. We present the case of a six-month-old female infant who presented with a solitary, firm, dome-shaped yellowish-brown nodule on the back, noticed by her parents four weeks prior to consultation. The lesion was asymptomatic, with no history of trauma or discharge, and was not associated with systemic symptoms. Clinical examination and differential diagnoses included JXG, mastocytoma, Spitz nevus, nevus sebaceous, and xanthoma. A 3 mm punch biopsy was performed, and histological analysis revealed a pandermal infiltrate composed of epithelioid and foamy histiocytes intermingled with Touton-type giant cells, lymphocytes, eosinophils, and plasma cells. The overlying epidermis demonstrated hyperkeratosis and acanthosis, with no evidence of malignancy. The histiocytes were positive for CD68, confirming the diagnosis of JXG. This case underscores the importance of recognizing JXG as a differential diagnosis in pediatric dermatology and highlights the characteristic histological findings that facilitate diagnosis in a clinical context.