MR OF ESTHESIONEUROBLASTOMA (OLFACTORY NEUROBLASTOMA) AND APPEARANCE AFTER CRANIOFACIAL RESECTION

PURPOSE: To analyze the MR characteristics of a series of patients wit h esthesioneuroblastoma and discuss the typical surgery and its postop erative MR appearance. METHODS: The MR studies of 15 patients with the pathologic diagnosis of esthesioneuroblastoma (also known as olfactor y neuroblastoma) were retrospectively reviewed and correlated with CT and surgical findings. The postoperative MR studies of 10 patients who underwent craniofacial resection were also reviewed. RESULTS: In all cases the tumors arose in the superior nasal cavity and extended into the ethmoid cells. In some instances the tumors extended into the othe r paranasal sinuses, orbits, anterior cranial fossa, and cavernous sin us. The tumors were typically expansile and destructive in their growt h patterns. Compared with brain gray matter, the tumors were hypointen se on T1-weighted images and isointense to hyperintense on T2-weighted images. Nine tumors were heterogeneous and 6 were homogeneous. Contra st enhancement ranged from mild to marked. MR was useful for character izing the various tissues and distinguishing fluid in the postoperativ e nasal cavity. CONCLUSIONS: Esthesioneuroblastoma, although an uncomm on tumor, may be suspected in lesions of the superior nasal cavity dem onstrating both expansile and destructive growth properties. The MR fi ndings are otherwise nonspecific. MR is the imaging modality of choice for depicting local tumor extension and evaluating for recurrence aft er craniofacial resection.