Synchronous Olfactory Neuroblastoma and Olfactory Groove Meningioma

Olfactory neuroblastoma (esthesioneuroblastoma) and olfactory groove meningioma are rare tumors that arise from adjacent locations along the cribriform plate in the anterior skull base. Olfactory neuroblastoma originates from the olfactory neuroepithelium in the superior aspect of the nasal cavity, whereas olfactory groove meningioma originates from the cranial side of the cribriform. Tumors arising from either side of the cribriform plate can easily extend through its multiple foramina to involve the opposite side. Synchronous lesions presenting on both sides of the cribriform plate may present a diagnostic conundrum.

We report on an unusual case of a 64-year-old woman who presented with synchronous olfactory neuroblastoma (Kadish stage B) and olfactory groove meningioma (Simpson grade 0). The patient was treated with a purely endoscopic endonasal anterior craniofacial resection, including the intracranial portion and postoperative radiation therapy. Complete resection was obtained with negative margins. The skull base was reconstructed using dural substitutes and nasoseptal flap. No postoperative complications were observed. The patient was discharged at postoperative day 4. To our knowledge, this is the first reported skull base synchronous tumor treated with a purely endoscopic approach.