Skull Base Nodular Fasciitis in and Adolescent Male

Objectives: To report a case of nodular fasciitis (NF) arising from the skull base of an 11-year-old male.

Study Design: This was a case report and review of the literature.

Case: An 11-year-old male with a history of craniospinal radiation for medulloblastoma presented with severe epistaxis and a rapidly growing right nasal mass. Since presentation was consistent with possible secondary malignancy or vascular tumor, preoperative angiography was performed for consideration of embolization. The mass was removed through a transnasal endoscopic approach and found to arise from the right cribriform plate. Frozen section assessment favored a benign process, so a small fragment was left along the skull base to minimize the risk of CSF leak. Final pathologic diagnosis was consistent with NF.

Discussion: NF is a benign myofibroblastic lesion known to mimic sarcoma—the lesions are often rapidly progressive soft tissue masses that demonstrate increased cellularity and mitotic activity on histology. NF has long been suspected to be a reactive process resulting from local tissue injury; however, recent associations with MYH9-USP6 gene fusion have led to the idea that NF may instead be a neoplastic process. In the present case, the first reported originating from the skull base, several aspects of the patient's history suggested a more aggressive diagnosis. Fortunately, NF responds to surgical resection alone and recurrence is rare.

Conclusion: This is the first documented case of NF arising from the cribriform plate. The unusual location in addition to the concerning clinical characteristics made this a challenging diagnostic dilemma. Fortunately, with frozen pathology, and the use of highly specific molecular testing, the correct diagnosis was made and the patient was spared potentially significant morbidity.