A Pure Endoscopic Endonasal Resection of an Esthesioneuroblastoma Invading the Anterior Cranial FOSSA

Introduction: Esthesioneuroblastoma (olfactory neuroblastoma) is a malignant neoplasm, possibly originating from the basal neural cells of the olfactory mucosa that compromises the superior portion of the nasal cavity. Even rare among sinonasal malignancies accounting for approximately 3% of all nasal cavity tumors, has a slight male and probably no ethnicity or age predominance. A combination of surgical resection, radiotherapy, and chemotherapy is used for its treatment. With modern endoscopic-endonasal techniques, a minimally invasive safe single-stand gross total resection can be achieved. We present an operative video describing a pure endoscopic endonasal transcribiform approach for the resection of an esthesioneuroblastoma Kadish C. Case Presentation: A 40-year-old male with no relevant past medical history presented with a 6-month evolution of bilateral recurrent spontaneous nonpainful epistaxis, progressive nasal obstruction, and anosmia. His physical examination did not reveal any abnormal findings other than anosmia. A first nasal flexible fiberoptic endoscopy revealed a solid expansive lesion occupying both nasal cavities. A high-resolution sinus CT scan, brain, and paranasal sinuses contrast-enhanced MRI revealed an expansive lesion compromising the anterior and posterior ethmoidal cells, anterior aspect of the sphenoidal sinus, inferior nasal meatus and fovea ethmoidalis, extending bilaterally into the anterior cranial fossae floor, compromising the cribiform plate. T1-hypointense, T2-heterogeneusly hyperintense, and avid contrast enhancement showing dural involvement. Regional metastases were ruled out. An endoscopic endonasal biopsy characterized the lesion as an esthesioneuroblastoma, classifying it as Kadish C–Dulguerov T4N0M0–Hyams IV. A pure endoscopic endonasal transcribiform approach was performed, obtaining a gross total resection. The patient recovered well, with no other neurologic deficit or CSF leaks. Both histopathology and immunohistochemistry confirmed an olfactory neuroblastoma Hyams' IV, WHO grade III with focal rhabdomyoblastic differentiation. He received conventional radiotherapy and chemotherapy with no evidence of recurrence at 6-month follow-up. Discussion: A pure endoscopic endonasal transcribiform approach allows a safe, minimally invasive, single-stand gross total resection of this kind of sinonasal malignancies with osseous, dural or even brain involvement, avoiding brain retraction, associated with transcranial approaches. Associated surgery risks include CSF leak, infection and inability to achieve negative margins. As any other surgery for resection of sinonasal lesions is associated with rhinologic consequences such as usually transient intranasal crusting or even “empty nose syndrome,” all according to the grade of resection of intranasal contents, pursuing negative margins. Fig. 1 Fig. 2 Fig. 3 Publication History Article published online: 12 February 2021 © 2021. Thieme. All rights reserved. Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany