Walsh & Hoyt: Tumors of the Olfactory Groove

Patients with tumors of the olfactory groove have symptoms and signs similar to those of patients with frontal lobe tumors. Most tumors in this region are meningiomas, although neuroblastomas and other tumors may also occur. Olfactory groove tumors almost always attain a considerable size before they are discovered, because the area in which they grow is both neurologically and visually ""silent."" The first clinical symptom is a reduction of the sense of smell on one or both sides that eventually leads to anosmia. This may be perceived by the patient as a problem with taste. Unfortunately, the anosmia is often ignored by the patient and overlooked by the physician. Since the most common cause of anosmia is chronic rhinitis, even when anosmia is appreciated by the physician, the possibility of an underlying neoplasm is rarely considered. Anosmia may be the sole neurologic sign of an olfactory groove tumor for many years. Only when a patient develops symptoms and signs of increased ICP (headache, nausea, vomiting), progressive visual loss from pressure on the intracranial optic nerves, optic chiasm, or evidence of frontal lobe dysfunction (seizures, incontinence, or disturbances in memory, affect, and behavior) is an intracranial lesion suspected. By the time of diagnosis, the tumor has usually grown so large that removal is difficult, with a greater likelihood of permanent neurologic and visual deficits.