頭蓋内，眼窩内進展および多発性転移を伴ったolfactory neuroblastomaの1例

A case of olfactory neuroblastoma with intracranial, intraorbital extension and multiple metastases

I．はじめに

　Olfactory neuroblastoma（ONB）は上鼻腔に発生する腫瘍であるが，他部位への転移をきたしたり，稀に頭蓋内にも浸潤することがある．このような進展例は予後不良とされているが，最近は化学療法を併用した試みがなされ，有効との報告も散発的ながらみられるようになってきた．われわれも頭蓋内，眼窩内に進展し，全身に多発性転移をきたしたONBに対して，化学療法を併用した症例を経験したので，報告するとともに文献的考察を行った．

A 51-year-old man presented with headache, vomit-ing and exophthalmus. Neurological examination re-vealed anosmia, papilledema, decrease in visual acuity, and disability in ocular movement. MRI showed a huge mass which occupied the whole nasal cavity and com-pressed the frontal lobe upwards and the eyes laterally. CT revealed an extensive bony destruction of the fron-tal base and bilateral orbits. The mass was biopsied transnasally, and was histologically diagnosed as olfac-tory neuroblastoma. It was highly radiosensitive and disappeared with a local irradiation of 40 Gy. Three months later the patient complained of a pain radiating from the neck to the right arm. MRI demonstrated a metastasis at the vertebral body of C5. Local irradiation of 30 Gy was performed. The metastatic lesion was re-moved, and a bone graft taken from the iliac bone was transplanted via an anterior cervical approach. Three weeks later, however, a hard mass appeared in the right of his neck and was surgically removed. By histo-logical examination, it was also identified as a metasta-tic neuroblastoma to the cervical lymphnode. A week after the removal of the cervical metastatic lesion, the metastasis extended rapidly to the left cervical and the bilateral hilar lymphnodes of the lungs. Chemotherapy was performed with a total doses of 800mg of cy-clophosphamide, 1.5mg of vincristine, 40mg of pirarubi-cin, and 80mg of cisplatin. The lesions disappeared within 7 days. However, the patient died from dissemi-nated intravascular coagulation 10 months after the onset.

Olfactory neuroblastoma is usually an intranasal neo-plasm, but it rarely extends intracranially and intraorbi-tally as is shown in our case. Basically, olfactory neuro-blastoma is a relatively slow-growing tumor though it has a tendency to develop local recurrences over long periods even after aggressive primary treatment, and accompanied with distant metastases. However, our pa-tient showed a very short survival time. Invasive ex-tension and multiple metastases occurred during a short period, followed by disseminated intravascular coagula-tion. Combined chemotherapy at the initial treatment may be recommended in such an extensive case.