Endolymphatic sac tumours (ELST) is a very rare group tumoura tissue mass that forms from groups of unhealthy cells that develops in the endolymphatic sac, which is a balloon shaped structure in the inner ear. These tumours are often classified as benignnot cancerous, can grow but will not spread to other body parts, however they can become malignantcancerous, may grow and spread to other areas of the body.
The endolymphatic sac and duct are filled with fluid that surrounds and protects other structures in the inner ear, which affect hearing and balance. They are responsible for releasing fluid to regulate pressure and volume in the inner ear, removing excess fluid and waste products from the inner ear, and regulating the immune response in the inner ear.
ELSTs are often associated with Von Hippel-Lindau (VHL) syndrome, which is a rare genetic disorder that causes the development of multiple benign and malignant tumours throughout the body.
ELSTs are often diagnosed equally between the sexes, and are often diagnosed around 30 years of age. However, anyone can develop this disease.
Treatment
When cancers are detected, they are staged and graded based on size, metastasiswhen the cancer has spread to other parts of the body, also known as mets, and how the cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs cellsthe basic structural and functional unit of all living things look under the microscope. Stagingthe process of determining how big the cancer is, where it started and if it has spread to other areas and grading helps your doctors determine the best treatment for you. However, as ELSTs are considered benign, these tumours are generally considered low-grade and not staged.
Once your tumour has been diagnosed, your doctor may recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment is dependent on several factors, including tumour size, age, stage of disease and overall health.
Treatment options for ELSTs may include:
- Surgerytreatment involving removal of cancerous tissue and/or tumours and a margin of healthy tissue around it to reduce recurrence, potentially including:
- Mastoidectomysurgery to remove diseased or dead cells in the air-filled spaces of the mastoid bone of the skull.
- Lateral temporal bone resection (LTBR)complete or partial removal of the temporal bone, often including the ear drum and other tissues/structures used for hearing.
- Nerve repair surgerysurgery to repair any nerve damage that occurs as a result of a tumour or prior surgery.
- Radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells.
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
Risk factors
Because of how rare ELSTs are, there has been limited research done into the riskthe possibility that something bad will happen factors of this disease. However, there has been a definitive link between the development of ELSTs and patients who have been diagnosed with VHL.
Symptoms
ELSTs may appear asymptomatic in the early stages of disease. As the tumour progresses (often rapidly), some of the following symptoms may appear:
- Hearing loss.
- Tinnitusringing in one or both ears.
- Dizziness.
- A feeling of pressure in the ear.
- Facial paralysis (rare).
Patients with VHL may experience additional symptoms depending on the tumours present.
Not everyone with the symptoms above will have cancer, but see your general practitioner (GP) if you are concerned.
Diagnosis
If your doctor suspects you have an ELST, they may order the following tests to confirm the diagnosisthe process of identifying a disease based on signs and symptoms, patient history and medical test results and refer you to a specialist for treatment:
- Physical examinationan examination of your current symptoms, affected area(s) and overall medical history.
- Neurological examinationan assessment of sensory and motor functions, such as vision, balance and coordination.
- Imagingtests that create detailed images of areas inside the body tests, potentially including:
- MRI (magnetic resonance imaging)a type of medical imaging that uses radiowaves, a strong magnet and computer technology to create detailed images of the body.
- CT (computed tomography) scana type of medical imaging that uses x-rays and computer technology to create detailed images of the body.
- Blood teststesting done to measure the levels of certain substances in the blood.
- Biopsyremoval of a section of tissue to analyse for cancer cells.