再手術後7年を経過してspinal metastasisを来したolfactory neuroblastomaの1例

Olfactory Neuroblastoma with Spinal Metastasis: Case Report

Ⅰ．はじめに

　Olfactory neuroblastomaは上鼻腔に発生する稀な腫瘍で，様々な部位に遠隔転移を来し，また初回治療後10年後に再発を来す例も報告されているが¹⁶⁾，長期を経過して脊髄転移を来した症例は稀である．今回われわれはolfactory neuroblastomaの初回手術後8年を経過して出現した頭蓋内および眼窩内転移巣に対して，手術および放射線治療を施行し，さらにその7年後に馬尾転移を来した症例を経験したので，文献的考察を加えてここに報告する．

　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 32Gy and lumber-spine irradiation of 10Gy 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.