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What is esthesioneuroblastoma (olfactory neuroblastoma)?
Esthesioneuroblastoma, also called olfactory neuroblastoma, is a rare cancer that begins in the olfactory (smell) nerve tissue high in the nasal cavity, near the thin bone that separates the nose from the brain. Despite the name, it is unrelated to the childhood cancer neuroblastoma. It usually grows slowly and most often causes a blocked nose, nosebleeds, or a reduced sense of smell, which can delay diagnosis. Because it sits in a delicate area surrounded by the eyes, brain, and major nerves, treatment is carefully planned by a team and usually combines surgery to remove the tumor with radiation; chemotherapy is added for higher-grade or advanced disease. With modern surgery and radiation, many patients do well, though long-term follow-up is important because it can return years later.
The main types
Doctors group esthesioneuroblastoma (olfactory neuroblastoma) by where it starts and how it behaves:
| Type | What it means, simply |
|---|---|
| Low-grade (Hyams grade 1-2) | Cells look closer to normal and the tumor grows more slowly; often very treatable with surgery and radiation. |
| High-grade (Hyams grade 3-4) | Cells look more abnormal and the tumor is more aggressive, with a higher chance of spreading to lymph nodes; usually needs surgery, radiation, and chemotherapy together. |
Staging, in plain terms
Esthesioneuroblastoma is most often described with the Kadish staging system rather than ordinary TNM. Kadish groups the cancer by how far it has spread out from the nasal cavity: stage A stays in the nose, stage B reaches the sinuses, stage C extends beyond the sinuses (to the eye socket or toward the brain), and stage D means spread to lymph nodes or distant sites. Doctors also grade the tumor (Hyams grade) under the microscope, and both the spread and the grade guide how intensive treatment needs to be.
| Kadish system (modified) — not standard TNM | What it generally means |
|---|---|
| Kadish A | Limited to the nasal cavity. Often treated with surgery and radiation with excellent control. |
| Kadish B | Extends into the paranasal sinuses. Treated with surgery and radiation, with chemotherapy considered for higher-grade tumors. |
| Kadish C | Reaches beyond the sinuses toward the eye socket or the base of the skull/brain. Needs combined surgery, radiation, and often chemotherapy at an expert center. |
| Kadish D | Spread to lymph nodes in the neck or to distant organs. Treated with combined therapy including radiation to the neck and systemic treatment. |
The standard of care
Esthesioneuroblastoma (Olfactory Neuroblastoma) is almost always treated by a team that may include a surgeon, a medical oncologist, and a radiation oncologist, combining therapies for the best result. The usual building blocks are:
Surgery (often endoscopic)
Removing the tumor — increasingly through the nostrils with endoscopes, or with a combined approach for larger tumors — is the foundation of treatment, aiming for clear margins while protecting the eyes and brain.
Radiation therapy
Radiation is a central, often curative part of treatment, given after surgery to clear any microscopic disease or as the main treatment when surgery is not possible. It also treats the neck when lymph-node spread is a concern.
Chemotherapy for high-grade or advanced disease
For aggressive (high-grade) or widespread tumors, chemotherapy is added — before or with other treatments — to shrink the tumor and treat possible spread.
Long-term surveillance
Because esthesioneuroblastoma can recur many years later, regular imaging and exams of the nose, neck, and skull base continue well after treatment ends.
How radiation treatment works
Radiation damages the DNA inside cancer cells so they can no longer divide. For esthesioneuroblastoma, radiation is one of the most important treatments because the tumor sits in a delicate spot surrounded by the eyes, optic nerves, and brain, where surgery alone may not safely remove every cell. After surgery, radiation cleans up microscopic disease and lowers the chance of return; when surgery is not possible, it can be the main treatment. Advanced techniques — intensity-modulated radiation and especially proton therapy — shape the dose tightly to the tumor while sparing vision and brain tissue. Radiation is painless during delivery, given over several weeks of daily sessions, and external-beam treatment leaves no radioactivity in the body.
The main ways radiation is delivered for esthesioneuroblastoma (olfactory neuroblastoma):
Intensity-modulated radiation (IMRT)
Beams are sculpted around the complex anatomy of the skull base to deliver a high dose to the tumor bed while limiting dose to the eyes, optic nerves, and brain.
Proton therapy
Proton beams stop at a set depth, depositing little dose beyond the target — especially valuable here for sparing the nearby brain, optic nerves, and eyes.
Stereotactic radiosurgery (selected)
Highly focused radiation can treat a small residual or recurrent tumor in one or a few sessions when surgery is not ideal.
Latest studies shaping care
Care keeps improving — often toward getting the same excellent results with less burden on patients. A few developments:
Surgery plus radiation as the standard: Reviews and large series consistently show that combining surgery (often endoscopic) with radiation gives the best local control and survival, with radiation central to treating the skull-base region the surgeon cannot fully clear.[1]
Head & Neck / Laryngoscope esthesioneuroblastoma series and meta-analyses
Proton therapy to protect vision and brain: Particle-therapy studies report that proton beams reduce dose to the eyes, optic nerves, and brain compared with standard photon radiation, supporting their use for tumors near these critical structures.[2]
International Journal of Radiation Oncology, Biology, Physics — proton skull-base reports
Grade and neck treatment matter: Outcome analyses link higher Hyams grade and Kadish stage to greater risk of neck and distant spread, supporting elective neck radiation and added chemotherapy for high-grade tumors.[3]
Cancer / Head & Neck outcome analyses
Common questions
Is this the same as neuroblastoma in children? No. Despite the similar name, esthesioneuroblastoma (olfactory neuroblastoma) is a different disease that starts in the smell-nerve tissue of the nose, usually in adults. It is not the childhood cancer neuroblastoma and is treated very differently.
Why is radiation so important here? The tumor grows in a narrow, delicate space next to the eyes, optic nerves, and brain, where surgery alone may not safely remove every cell. Radiation — especially precise techniques like proton therapy — clears microscopic disease and protects vision and brain function, which is why it is usually combined with surgery.
Will I lose my sense of smell? Because the cancer arises in the smell nerves and treatment involves that area, the sense of smell on the affected side is often reduced or lost. Your team will discuss what to expect and how treatment is planned to protect as much function as possible while removing the cancer.
References
Numbered sources for the studies cited above. Links open the primary publication on PubMed or the publisher’s site.
- Head & Neck / Laryngoscope esthesioneuroblastoma series and meta-analyses (no indexed identifier — see your care team) ↩
- International Journal of Radiation Oncology, Biology, Physics — proton skull-base reports (no indexed identifier — see your care team) ↩
- Cancer / Head & Neck outcome analyses (no indexed identifier — see your care team) ↩