[A case of olfactory neuroblastoma presenting symptoms of a brain metastasis--a case report].

A rare case of olfactory neuroblastoma presenting symptoms as a brain metastasis is reported. A 47-year-old-man was admitted to Yamagata City Hospital complaining of head heaviness and headache attack. Neurologically, bilateral slight choked disc and right anosmia were found. The otolaryngologist in this hospital pointed out a reddish-purple polypoid tumor in the right nasal cavity. But there were no episodes of nasal bleeding or obstruction before admission. CT scan on admission showed the tumor density in the right upper nasal cavity and ethmoid sinus, which partially infiltrated into the orbital cavity, and enhanced heterogenous high density mass in the inner basal portion of the right frontal lobe. Carotid angiogram revealed a small tumor blush in the ethmoid region and avascular mass lesion in the right frontal region. On the 11th hospital day, surgical biopsy of the nasal tumor was performed by the otolaryngologist and the evident tumor cells in the fibrous tissue were observed. So the endonasal removal of the tumor and the total removal of the intracranial tumor were achieved. On operation, the continuity of intracranial tumor and nasal tumor was not observed. The histological pictures of both tumors were similar and the diagnosis was olfactory neuroblastoma. From histological and operative findings, we concluded the intracranial tumor was metastatic lesion from nasal origin. CT scan taken after the operation showed the tumor rested only in the right ethmoid sinus.(ABSTRACT TRUNCATED AT 250 WORDS)