Rapid Growing Eosinophilic Granuloma in Skull after Minor Trauma

The authors present a case of rapidly progressing eosinophilic granuloma (EG) of the skull without hemorrhage after minor trauma. A 6-year-old boy presented with a soft mass on the midline of his forehead. He had a surgery for EG 19 months ago. One month earlier, computed tomography (CT) and bone scans were performed to evaluate the possible recurrence of EG, and there was no evidence of recurrence in CT. However, a slightly increased uptake in the bone scan was noted on the midline of the forehead. A rapid growing mass developed in a new spot after a minor trauma 7 days before the patient arrived at the clinic. His physical examination was unremarkable, except for a non-tender, soft, and immobile mass. A plain skull X-ray and CT showed a lytic bony defect on the midline of the frontal bone. Magnetic resonance imaging showed a 1.4 cm sized enhancing mass. Surgical resection and cranioplasty were done. The role of trauma in the development of EG is unclear. However, our case suggests that minor trauma is an aggravating factor for EG formation. Careful observation with regular follow-up is necessary in patients with EG after minor trauma.