Fig. 5

Images from Case 2. An olfactory neuroblastoma. a Enhanced coronal MRI reveals a mass with irregular margins on the left side of the upper nasal cavity extending to the frontal base. d The tumor can be seen invading the frontal base and extending to the anterior wall of the sphenoid sinus. b, e A well-enhanced PNSF and coverage state of the ASB defect can be seen in the postoperative coronal and sagittal MRI. c, f The follow-up coronal and sagittal MRI revealed stable disease status and well-healing state of the nasal mucosa 6 months after the operation. ASB: anterior skull base, PNSF: pedicled nasoseptal flap