Glossary

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Endocrine-Inactive Adenoma (Non-Functioning Adenoma): a pituitary adenoma that does not result in excess hormone production. Instead these adenomas cause symptoms because of pressure on the normal pituitary gland and on structures near the pituitary such as the optic nerves and optic chiasm. Primary treatment is by endonasal transsphenoidal surgical removal. Learn more.
Endocrinology: the practice of medicine dealing with hormonal disorders and the endocrine system. The endocrine system is composed primarily of the hypothalamus, pituitary gland, thyroid gland, parathyroid glands, adrenal glands, pancreas, ovaries and testes.
Endonasal Surgery: performing intracranial surgery through a nostril using the operating microscope or endoscope or both. Endonasal surgery is a subset of transsphenoidal surgery which means operating through the sphenoid sinus (behind the nasal cavity). Virtually all pituitary adenomas and Rathke’s cleft cysts, the majority of craniopharyngiomas and clival chordomas as well as many other tumor types such as suprasellar meningiomas and sinus carcinomas can now be removed through a nostril. Learn more.
Endoscope & Endoscopic Surgery: an instrument and a technique used for minimally invasive removal or tumors. The endoscope provides a wide-angled panoramic surgical view not possible with the relative tunnel vision of the operating microscope. Endoscopic visualization is mandatory for the safe and effective endonasal removal of tumors located far above or below the pituitary gland. Learn more.
Ependymoma: one of the 3 major types of gliomas: astrocytomas, ependymomas and oligodendrogliomas. Ependymomas arise from the ependymal lining of the ventricles (fluid-filled chambers of the brain). Treatment of ependymomas usually involves surgical debulking, radiotherapy and sometimes chemotherapy. Learn more.
Epidermoid Cyst: relatively uncommon benign cysts or tumors that arise from stratified squamous epithelium over the surface of the brain. As the epithelial lining continues to produce the soft white keratin material, the cyst puts pressure on the adjacent brain structures and can cause headaches, weakness, imbalance, visual loss or seizures depending upon the cyst location. Some epidermoid cysts can rupture and result in a meningitis type reaction from inflammation. The most common locations are around the brainstem, pituitary gland and in the posterior fossa along the cerebellum. Large epidermoid tumors causing symptoms are treated by surgical removal which is generally quite successful in resolving symptoms. Learn more.
Esthesioneuroblastoma (Olfactory Neuroblastoma): an uncommon brain tumor arising from the olfactory nerve that can cause headaches, nasal obstruction and nasal bleeding. Multi-modality treatment with surgery, radiotherapy and chemotherapy is typically indicated. Learn more.
Estrogen: a hormone produced by the ovaries. Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH) control production of sex hormones (estrogen and testosterone) as well as sperm and egg maturation and release. Also known as Estradiol (E2), estrogen is critical for female reproductive and sexual functioning and for bone structure. Estrogen, like other steroids, is derived from cholesterol. Learn more.
Ethmoid Sinus: one of the air sinuses located adjacent to the nasal cavity. The ethmoid sinus and its multiple ethmoidal air cells sit above the nasal cavity, between the orbits and below the frontal fossa where the frontal lobes reside. The other paranasal sinuses are the paired maxillary sinuses and the sphenoid sinus.