Eruptive xanthogranuloma in a healthy adult male

Xanthogranuloma is a benign, non-Langerhans cell histiocytosis primarily diagnosed in infants and children, although a subset occurs in adults. Multifocal eruptive presentation of xanthogranuloma is very rare with only 4 previous cases reported in the literature to our knowledge. We describe a case of eruptive xanthogranuloma in a 49-year-old man who presented with sudden onset of numerous asymptomatic, red-yellow to orange papules on the face, scalp, axilla, flank and scrotum. Histologic features were consistent with xanthogranuloma with diffuse mixed infiltrate of foamy histiocytes, Touton giant cells and lymphocytes. Other than temporarily elevated non-fasting triglycerides, lab values have been unremarkable including serum plasma electrophoresis; however, the patient will continue to be monitored for ocular and other extracutaneous involvement and hematologic malignancies.