Abstract

Juvenile xanthogranuloma (JXG) is most common in the first two decades of life and present most often on the head and neck. In 2002, Miguolez at al. newly described a JXG with a high mitotic index on the shoulder of a 2-year-old-girl. Subsequently, three cases of mitotically active JXGs have been reported in the literature. Herein, we present the fifth known case of a mitotically-active JXG. A five-month-old male was brought in by his caregiver with a six-week history of a growing papule on the eyebrow, with associated intermittent crusting. Tangential biopsy was performed with histopathological examination consistent with non-lipidized JXG. However, mitotic figures were conspicuous, with a notably high proliferative index of 38 mitoses per 10 high-power fields. The immunoprofile of the cells revealed positive staining with CD68 and negative staining with both S100 and CD1a and was consistent with a histiocytic lineage of the cells. Our case is the first published of this subtype located on the face. It is of the utmost importance to distinguish these exceedingly rare benign neoplasms from histiocytic sarcoma and melanoma.

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