[A case of olfactory neuroblastoma with intracranial extension and distant metastasis].

Olfactory neuroblastoma is a rare tumor originating in the upper nasal cavity. It rarely extends intracranially. We report a clinical case of olfactory neuroblastoma with intracranial extension and distant metastasis. A 35-year-old man complained of nasal stuffiness and bleeding, headache and vomiting. Neurological examination showed anosmia and papilledema. MRI showed a huge mass that occupied the right nasal and paranasal cavities, and extended into the right frontal base. The tumor was removed totally and was histologically diagnosed as olfactory neuroblastoma. About two months after surgery, however, MRI demonstrated a rapid recurrence of the tumor in the nasal and paranasal cavities and the frontal lobe. Metastatic lesions were also seen in the right cervical lymph nodes. Chemotherapy was administered using cisplatin and etoposide. The tumor in the frontal lobe shrunk markedly but the other lesion persisted. Whole brain irradiation and local irradiation of the cervical lymph nodes were performed. The tumors became smaller but did not disappear. MRI demonstrated spinal dissemination. Irradiation of the whole spinal cord was performed. The metastatic lesions disappeared. The patient was discharged without neurological deficits, but died of pneumonia 15 months after surgery. Olfactory neuroblastoma is a slow-growing tumor and is highly radiosensitive, but it rarely extends or develops multiple distant metastases and seldom shows a short survival time, as in our case. A review of the literature documented responses in patients treated with a cisplatin-based drug combination. We recommend systemic control using cisplatin-based chemotherapy in addition to irradiation to prevent local recurrence in cases of advanced or metastatic olfactory neuroblastoma.