[Olfactory neuroblastoma with spinal metastasis: case report].

Olfactory neuroblastoma is a rare tumor of the nasal cavity. It is a locally aggressive tumor with local recurrence, and distant metastasis occurs in 22-40% of patients. We report a case of olfactory neuroblastoma with cauda equina metastases. A 49-year old male had undergone surgery twice previously; the first for olfactory neuroblastoma in October, 1990, and the second for its intracranial and orbital metastasis in September, 1999. He complained of lumbago in autumn, 2005 and MRI showed two enhanced lesions in the cauda equina. The mass was partially removed and histologically diagnosed as olfactory neuroblastoma metastasis. Whole-spine irradiation of 32 Gy and lumber-spine irradiation of 10 Gy were performed. The mass at L2/3 was disappeared after the irradiation although the mass at L4/5 was not changed in size. The patient was discharged without neurological deficit and is now kept under observation as an outpatient. Olfactory neuroblastoma with spinal metastasis is rare and only 11 cases have been reported in the literature. A very poor prognosis was observed in the patients of olfactory neuroblastoma with spinal metastasis. Olfactory neuroblastoma is a radiosensitive tumor, and radiotherapy for spinal metastasis was reported to be effective. However, effectiveness of chemotherapy was still uncertain. The patient with olfactory neuroblastoma should be observed carefully even though no local recurrence had been detected over 10 years. Radiotherapy and further treatment including chemotherapy should be considered in case of spinal metastasis.