Angiomatoid fibrous histiocytoma mimicking eosinophilic granuloma in a pediatric patient-A case report.

Abstract

BACKGROUND\nAngiomatoid fibrous histiocytoma (AFH) is a rare low-grade malignant tumor mainly occurring in soft tissues, and its incidence in the bones is extremely rare. While most of the existing reports focus on the pathological features of AFH, only a few describe its imaging features. This is the first case of AFH in the skull, and it is distinguished from eosinophilic granuloma based on imaging results.\n\n\nCASE SUMMARY\nA 10-year-old boy presented a painless mass of parietal bone after the trauma. Cranial CT angiography (CTA) showed local bone defects near the sagittal suture of the left parietal bone and a soft tissue mass with relatively uniform density in the same area. The signals of this mass were heterogeneous in all sequences of MRI and presented septal enhancement after the injection of contrast agent. The patient underwent complete resection of the mass and the histopathological and immunohistochemical diagnosis of the mass was AFH. No complications occurred after the operation and no recurrence occurred during the follow-up.\n\n\nCONCLUSION\nThis is the first AFH that occurs in the skull, and the mainly imaging manifestations of AFH are bone destruction with soft tissue mass. The characteristic features of AFH are its fibrillar component which showed low signal on T2WI and septal or peripheral enhancement, and no dead bone in the mass.