[Intracranial invasion of neuroendocrine carcinoma: a case report].

A rare case of neuroendocrine carcinoma arising from the nasal cavity is reported. A 57-year-old female, who had been complaining of anosmia for 8 years, was admitted to the otolaryngological department because an intranasal tumor was found. Then, removal of the tumor and radiotherapy was carried out. After these procedures, the patient suffered from a high fever and CSF rhinorrhea. At this stage, our neurosurgical department was consulted. CT scan revealed a partially calcified low density mass with a slight enhancement effect at the left frontal base. Under the diagnosis of intracranial invasion by intranasal neuroendocrine carcinoma, the patient was operated on. Through bifrontal craniotomy and a combination of extra- and intradural approach, the tumor was excised. After that, the dura and the skull base were reconstructed. On histological examination, the tumor was found to consist of NSE positive cells forming some glandular structures. Electron microscopic study disclosed neurosecretory granules in the cytoplasmic process. These findings are typical of neuroendocrine carcinoma and compatible to those of the intranasal tumor previously removed. Neuroendocrine carcinoma is rare in itself and there have been reported only two cases of its invasion of the skull base. The clinical features, diagnostic procedures, pathological findings, and treatment of this tumor are discussed in this report.