Final answer:
The term for a tumor originating from nerve cells is either 'neuroblastoma' for immature nerve cells or 'glioma' for tumors from glial cells, and can be benign or malignant.
Step-by-step explanation:
The word for a tumor of nerve cells is neuroblastoma when the tumor arises from immature nerve cells, or glioma if it originates from glial cells, which are the supportive cells in the nervous system. While a neuroblastoma is more common in children, gliomas can occur at any age. Tumors of nerve cells can be either benign, meaning they do not invade other tissues and do not form metastases, or malignant, which are considered cancerous, can spread and invade other tissues.