Warthin Tumor
Information on the causes, symptoms, and most effective treatments for a cyst in the salivary glands.
Symptoms and Causes
Warthin tumor is a benign cyst that develops in the salivary glands and affects lymphoid tissue. Although it can occur in any of them (parotid, sublingual, and submandibular glands), it is most frequently found in the parotid gland, located below the ear and behind the lower jaw. It most commonly appears on only one side. It is estimated that only between 5% and 14% of cases are bilateral.
Warthin tumors are composed of epithelial cells that project inward in the form of papillae, surrounded by a lymphoid stroma. Centrally, the spaces are filled with viscous yellow or brown fluid.
In most cases, Warthin tumors grow very slowly and only very rarely develop malignant cells. Therefore, when treated early with surgery, the prognosis is usually very good, with complete cure and no recurrence.
Symptoms
The most characteristic symptoms of Warthin tumor are:
- A lump in the jaw, neck, or mouth.
- Muscle weakness on one or both sides of the face.
- Numbness.
- Persistent pain in the jaw or ear.
- Difficulty opening the mouth.
- Difficulty swallowing.
- Hearing disturbances.
- Tinnitus: ringing inside the ear.
Causes
The specific causes of Warthin tumor are unknown, although tumor formation is associated with changes in cellular DNA. These alterations may activate oncogenes (mutations of proto-oncogenes responsible for cell division) or deactivate tumor suppressor genes.
Studies indicate that Warthin tumors often show the presence of the MECT1–MAML2 fusion oncogene or the MYB–NFIB oncogene.
Risk Factors
Risk factors associated with Warthin tumor include:
- Sex: incidence is estimated to be four times higher in men, although this trend has been changing in recent years.
- Age: more common between 60 and 70 years of age.
- Smoking: the development of this cyst is directly related to tobacco use.
- Exposure to radiation to the head or neck.
- Genetic predisposition.
- Some studies associate the development of these tumors with certain viral infections, such as HIV, human papillomavirus (HPV), or, very rarely, Epstein–Barr virus.
Complications
The most notable complications of Warthin tumor, usually sequelae of surgical treatment, include:
- Facial paralysis: the most common complication. When it occurs, facial drooping and difficulty closing the affected eye are observed. It is a sudden paralysis on one side of the face that usually lasts hours or days, but may become permanent if the facial nerve is completely damaged.
- Salivary fistula: an abnormal opening in the gland that causes saliva to leak into the mouth through soft tissues instead of the normal duct, leading to accumulation.
- Low oxygen levels in the brain if the tumor is very extensive.
- Frey syndrome: caused by abnormal regrowth of nerves damaged during surgery, resulting in facial erythema and sweating while chewing.
- Difficulty swallowing or speaking.
- Changes in physical appearance.
Prevention
Although there is no specific way to prevent Warthin tumor, the risk can be reduced by following these recommendations:
- Stop smoking.
- Maintain a healthy diet.
- Reduce exposure to radiation whenever possible.
Which specialist treats Warthin tumor?
Warthin tumor, which is usually benign, is diagnosed and treated by specialists in Otorhinolaryngology and Oral and Maxillofacial Surgery. When malignant, Medical Oncology and Radiation Oncology specialists are also involved.
Diagnosis
Warthin tumor is diagnosed using the following procedures:
- Medical history (anamnesis): completion of the patient’s clinical history, including personal and family history, lifestyle, health status, and presenting symptoms.
- Physical examination: palpation of the jaw, neck, and throat to detect swelling or lumps, and inspection of the oral cavity.
- Computed tomography (CT scan): contrast-enhanced imaging is usually performed to detect tumor masses in greater detail.
- Magnetic resonance imaging (MRI): used to assess the characteristics of the neoplasm and determine whether it is a benign cyst or a malignant tumor.
- Biopsy: when imaging tests are inconclusive or to confirm the diagnosis, a sample of the lesion is obtained using fine-needle aspiration. The tissue is analyzed in the laboratory to determine the cellular nature of the tumor.
Treatment
The goal of Warthin tumor treatment is complete removal; therefore, the primary approach is surgical. When complete excision is not possible, usually due to invasion of adjacent structures, adjuvant therapies are required to slow tumor cell growth.
The most common treatments include:
- Surgical intervention: the procedure varies depending on the affected gland.
- Parotid gland surgery: access is obtained through an incision extending from the front of the ear to the neck. This approach is particularly complex because the facial nerve passes through the gland.
- Superficial parotidectomy: if the tumor affects only the superficial lobe, only this portion of the gland is removed.
- Total parotidectomy: when the tumor is more extensive, the entire parotid gland is removed and, if necessary, the facial nerve as well. In such cases, reconstruction should be considered to preserve functionality.
- Submandibular or sublingual gland surgery: the incision is made below the lower border of the mandible (using a natural neck fold) or in the floor of the mouth. The entire gland is removed and, if the tumor is large, nerves involved in tongue movement, lower facial movement, sensation, and taste may also be affected; reconstructive options are therefore evaluated.
- Minor salivary gland surgery: depending on tumor extent, parts of the lips, tongue, throat, or paranasal sinuses may need to be removed, especially if malignant cells are present. Reconstructive surgery is subsequently planned to restore, as much as possible, the ability to speak, swallow, chew, or move the face.
- Cervical lymph node surgery: performed in cases of malignant tumors that have spread to lymph nodes.
In the rare cases in which Warthin tumor is malignant, surgery is combined with other treatments such as:
- Radiotherapy: high-energy radiation (X-rays or gamma rays) is delivered externally to destroy cancer cells within the tumor.
- Chemotherapy: systemic cytotoxic drugs are generally not very effective for tumors originating in the salivary glands; therefore, they are used when cancer has spread to distant organs or when complete surgical excision of malignant cells is not possible, to prevent further growth rather than eliminate them.
- Targeted therapy: proteins expressed by cancer cells are identified (via biopsy), and specific drugs are administered to target this particular cancer type. The most commonly used agents target the androgen receptor, HER2 protein, or TRK inhibitors.
- Immunotherapy: medications are used to strengthen the immune system, enhancing its ability to fight tumor cancer cells.
