Primary Intracranial Neuroendocrine Tumor of the Skull Base Complicated with Tension Pneumocephalus after Radiotherapy

Abstract

Neuroendocrine tumors (NETs) are neoplasms that originate from cells of the endocrine and nervous systems, and are commonly found in the gastrointestinal and respiratory tracts. Primary intracranial NETs are extremely rare and have been the focus of only a few studies thus far. Herein, we report the case of a primary intracranial NET of the skull base complicated with tension pneumocephalus after radiotherapy. An 84-year-old woman visited a local hospital for a head injury, and CT revealed a skull base tumor. MRI showed that the tumor was located mainly on the clivus and extended into the paranasal sinuses and nasal cavity. We biopsied the tumor via the nasal cavity, and the pathological diagnosis was NET, WHO grade 2. We subsequently administered focal intensity-modulated radiation therapy, but the patient developed tension pneumocephalus 1 year after radiotherapy. We therefore performed endoscopic transnasal cerebrospinal fluid leak closure with a nasoseptal flap. The postoperative course was successful, and the patient returned home but died of an unknown cause 2 years after discharge. The optimal postoperative management of primary intracranial NETs remains controversial. Tension pneumocephalus related to radiotherapy is a rare complication. Assessing skull bone erosion before radiotherapy and performing regular radiological follow-up examinations are essential to prevent this rare complication.

Case of Cerebrospinal Fluid Leakage Nine Years after Pituitary Gamma Knife Surgery for Poststroke Thalamic Pain Syndrome

“… 7 ) The skull base bone erosion is also reported to be related to postirradiation CSF leakage. 8 ) Reduction in tumor volume by radiotherapy may cause a connection between the paranasal cavities and CSF space in cases of tumors with dural invasion or bone destruction. Stereotactic radiosurgery, especially GKS, is an established treatment option for intrasellar or parasellar tumors, including pituitary adenomas, craniopharyngiomas, and meningiomas.…”

“…Delayed CSF leakage has been reported as an infrequent complication of various radiotherapy, including stereotactic radiosurgery for the skull base or parasellar tumors. [1][2][3][6][7][8] In many of these cases, TSS is carried out before radiotherapy. Yamada et al reported a case of delayed CSF leakage after CyberKnife radiation for skull base osteosarcoma and mentioned tumor invasion to the dura mater as a risk factor for radiation-induced CSF leakage.…”