鼻腔から発生し，頭蓋内浸潤を来したsmall cell neuroendocrine carcinomaの1例

A Case of Intracranial Invasion from Sinonasal Small Cell Neuroendocrine Carcinoma

Ⅰ．はじめに

　神経内分泌腫瘍（neuroendocrine tumor：NET）は多くは内分泌臓器，消化器系臓器，呼吸器系臓器，乳腺，泌尿生殖器などから発生する稀な腫瘍である^2,12,13,15)．今回，neuroendocrine carcinoma（NEC）が鼻腔粘膜より発生し，拡大により前頭蓋底から頭蓋内浸潤を来した稀な症例を経験したため報告する．

　Sinonasal neuroendocrine carcinomas（NECs）are rare tumors. We present a rare case of intracranial invasion of sinonasal small-cell NEC. A 61-year-old woman with nasal obstruction and bleeding was referred to our hospital. Computed tomography showed a polyp-like tumor occupying her left nasal cavity and extending to the paranasal sinuses and anterior cranial fossa. The tumor was removed using a transfacial approach by otolaryngologists and a bifrontal cranial approach by neurosurgeons. In histopathological analyses, we found that the tumor presented with both an epithelial and neuroendocrine nature, and was diagnosed as a small-cell NEC. Post-surgery, she received localized radiation therapy and chemotherapy, and is alive, 18 months after diagnosis. In cases where it is difficult to perform a differential diagnosis of tumors arising from the frontal cranial base and extending to the nasal and cranial sides, NEC should be considered as a possibility.