Abstract

Xanthogranulomas are benign neoplasms of lipid-laden histiocytes with mixed inflammatory cell infiltrate that are often seen in young children, but may present at birth or later in adulthood. They may be solitary or multiple and may be limited to the skin or involve multiple organ systems. They are considered a form of non-langerhans cell histocytosis that can be distinguished by a lack of staining for langerin (CD207), as well as positive staining with HAM-56, CD68, and Factor XIIIa. Xanthogranulomas may present as different subtypes with varied histologic features including a rarely reported spindled cell variant that may be confused with other entities such as a dermatofibroma, Spitz nevus, Kaposi Sarcoma, other vascular lesions, or atypical fibroxanthoma. We present the case of a spindle cell xanthogranuloma that clinically appeared as an asymptomatic, but enlarging papule on the abdomen of an 11-year-old boy. A biopsy was performed and demonstrated a well circumscribed dermal nodule consisting predominantly of spindled cells with multinucleated Touton giant cells. The spindled cells and multinucleated histiocytes stained positively for CD68, but were negative for Sox10 stain. With these findings, the diagnosis of spindle cell xanthogranuloma was made. This case is presented for interest and discussion of features that may help prevent potential misdiagnosis.

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