What is Warthin Tumor?
The Warthin tumor, or cystadenolymphoma as it’s sometimes called, is a non-dangerous and common lump in the salivary gland. This condition was first documented by a doctor named Hildebrand in 1895. It makes up about 2% to 15% of all the primary tumors that occur in the parotid gland, a large salivary gland located in front of each ear. Occasionally, Warthin tumors can pop up in places outside of the parotid gland, like the lymph node near the parotid gland, the nasopharynx (the upper part of your throat behind the nose), your eyelid, and even your mouth. Under a microscope, Warthin tumors show a dense cluster of lymphoid (immune cells) stroma and a double layer of oncocytic epithelium (cells commonly found in tumors) arranged in a papillary (resembling small, nipple-like projections) and cystic (sac-like) pattern. However, no one is entirely sure how these tumors originate or develop.
What Causes Warthin Tumor?
The exact cause of Warthin tumor, a type of benign or non-cancerous growth, is still not completely understood. Some researchers propose that this tumor might develop due to certain factors that affect cells in nearby lymph nodes or the parotid gland, a major salivary gland located near the mouth and throat.
There are several potential causes for Warthin tumor that have been suggested. These include infection with the Epstein Barr virus, tobacco use, having an autoimmune disease where the body attacks its own cells, exposure to ionizing radiation which is a type of high-energy radiation, and chronic inflammation or long-term swelling and irritation.
However, there are still many unanswered questions. For example, it’s still not clear why Warthin tumors are more common in men, or why tobacco use seems to primarily affect the parotid gland rather than the smaller salivary glands inside the mouth.
It’s important to note that malignant or cancerous transformation of Warthin tumor is extremely rare, occurring only in 0.3% of cases, meaning it is generally a non-cancerous condition.
Risk Factors and Frequency for Warthin Tumor
Warthin tumor is a common type of benign, or non-cancerous, tumor found in the salivary glands. It makes up 2% to 15% of all parotid gland tumors, which are the largest of the salivary glands. The Warthin tumor is the second most common benign tumor in the salivary glands — with the pleomorphic adenoma being the most common. While Warthin tumors can occur at any age, they often appear in women in their 60s and men in their 70s. Still, the tumor is slightly more common in men than in women, although this difference is beginning to decrease.
- The Warthin tumor is a common benign tumor of the salivary glands.
- It represents 2% to 15% of all tumors in the parotid glands.
- It’s the second most common benign tumor in the salivary glands, after the pleomorphic adenoma.
- Warthin tumors can occur in people of all ages, but often appear in women in their 60s and men in their 70s.
- Men are slightly more likely to have a Warthin tumor than women, but this difference is decreasing.
Signs and Symptoms of Warthin Tumor
A Warthin’s tumor is usually felt as a smooth, round lump that doesn’t typically cause pain. The tumor, which can be found either on one or both sides of the body or in multiple places, is often not associated with symptoms. In fact, 90% of the individuals affected by this condition do not exhibit any signs. However, in some cases, it can lead to minor discomfort, a ringing sensation in the ear, ear pain, or even loss of hearing. The size of the lump can vary greatly, ranging from a few millimeters to several centimeters, though on average, they are typically between 2 to 4 centimeters.
- Smooth, round, painless lump
- Can be found on one or both sides, or in multiple places
- Usually no symptoms
- Ring in the ears, ear pain, and hearing loss in some cases
- Lump size varies from a few millimeters to several centimeters, but typically 2 to 4 centimeters
One study provided additional information about the common sizes for these tumors, highlighting that 56% of them were sized between 1 and 3 centimeters, and 40% were between 4 and 6 centimeters. There was also one particular case where the tumor was larger than 10 centimeters.
Testing for Warthin Tumor
High-resolution ultrasound is often the first choice for spotting growths in your salivary glands. But it can’t always reach the parts of the parotid gland, which is located deep in your jaw. Ultrasound of salivary gland masses also includes checking the opposite gland and the neck’s lymph nodes. If doctors need to identify the lesion before surgery, they could carry out an ultrasound-guided fine-needle aspiration cytology, a test that uses a thin, hollow needle to collect cells from a lump or mass.
In the case of Warthin tumors, an ultrasound may show a clear mass with multiple empty spaces, or an empty space with increased sound wave reflection at the lower part of the parotid gland. However, these patterns can change and fast growth can occur because of infection. In some cases, the tumor’s insides might appear uneven due to multiple partitions and varying levels of fluid inside. As Warthin tumors can often be found in more than one place and in both glands, the other gland should always be checked too.
Magnetic Resonance Imaging, or MRI, is another method of examination. Warthin tumors usually show up as enclosed lumps that have low or medium signals when scanned using T1-weighted techniques. With T2-weighted images, the tumor tends to have a medium signal intensity. Only about 30% of these tumors have small cystic parts, and these are seen with thin, uniform walls without any enhancement. A well-defined contour is a key detail to look for to differentiate benign parotid tumors, ones that are not harmful, from malignant, or harmful, tumors. MRI is useful for figuring out the features and content of the mass’s capsule and contour because it gives a high-resolution image of soft tissue. Both MRI and multislice CT scans have the ability to produce images of the tumors from multiple planes. The multislice CT also provides a good timeline for optimizing contrast and is a practical method.
Treatment Options for Warthin Tumor
Warthin tumor is a harmless growth that generally appears in one of your salivary glands (usually the parotid glands – located in front of your ears). The best treatment recommended for this is to surgically remove the tumor. The tumor is usually located closer to the surface, making its removal relatively easy. Some surgeons prefer a method called ‘superficial parotidectomy’ which helps prevent breaking the protective layer (or capsule) surrounding the tumor during surgery. Other surgeons might opt for local resection, which involves removing the tumor and some surrounding tissue.
It’s important to note that Warthin tumor is virtually always benign, or non-cancerous. In fact, the chances of it turning cancerous are just 0.3%. Therefore, some experts believe that removing it without distracting the capsule (a process called “enucleation”) is the best treatment option.
However, another study suggested that a more intensive surgical approach, called parotidectomy, can significantly reduce the chances of the tumor coming back. A parotidectomy involves removing part or all of the parotid gland, which might be necessary because Warthin tumors can appear in more than one place and on both sides of the face.
The decision of whether a superficial parotidectomy (removal of the outer part of the gland) or a deep parotidectomy (removal of the inner part of the gland) is the best approach can depend on exactly where the tumor is. If the tumor is located in the deep lobe of the gland, surgeons may first perform a superficial parotidectomy followed by a deep parotidectomy while ensuring safety of facial nerves.
If the tumor is located at the bottom of the parotid gland, a partial parotidectomy can be a good option. In a partial parotidectomy, the lower branches of the facial nerves and the tumor itself, along with some of the neighboring normal tissues are removed.
What else can Warthin Tumor be?
In diagnosing Warthin tumors, doctors also have to think about other conditions that might look similar. This includes:
- Lymph node metastases: These usually show abnormal cell growth and they lack a certain property called a bilayered, oncocytic epithelial element.
- Sebaceous lymphadenoma: This condition also lacks the bilayered, oncocytic epithelial element.
- Cystadenomas of the salivary glands: While these can show an oncocytic property, they lack lymphoid stroma (a type of tissue) and usually have small, spaces filled with fluid (cysts).
- Lymphoepithelial cysts: These are cysts that originate in the tissues of the lymph or epithelial system.
This is why accurate diagnosis is essential, as each condition may require different treatment options.
What to expect with Warthin Tumor
Warthin tumors are known to have a positive outlook and they rarely come back. It’s extremely rare for these tumors to become malignant, or cancerous. In such cases, regular check-ups are crucial to spot any spread of the cancer. Some experts believe that simply removing the Warthin tumor or monitoring it without removal could be enough.
Possible Complications When Diagnosed with Warthin Tumor
Local recurrence of a medical condition refers to the return of the health problem in the same area. This occurrence is rare. If it does happen, it’s usually due to either more than one tumor present at the same time (multifocal tumors) or the initial tumor was not entirely removed.
On the other hand, Malignant Transformation is a term for when a benign (harmless) tumor turns into a dangerous cancerous tumor. For Warthin tumors, a type of benign tumor, this transformation is exceedingly rare. Despite its rarity, a few instances have been reported affecting both the lymphoid (part of the immune system) and epithelial (surface cells) components of the tumor. The most common types of malignant transformation in a Warthin tumor are:
- Mucoepidermoid carcinoma
- Squamous cell carcinoma
- Undifferentiated carcinoma
- Oncocytic adenocarcinoma
- Adenocarcinoma
Each of these represents different potential types of dangerous cancer that can occur.
papillary structures lined by oncocytic epithelial cells. The stroma contains a
dense population of lymphocytes (hematoxylin and eosin ×40).
Preventing Warthin Tumor
If you notice any swelling in your parotid gland (which is one of your salivary glands), it is important to see an ear, nose, and throat specialist, also known as an otolaryngologist. Your healthcare team will make sure you understand what could be causing this swelling, such as a Warthin tumor. This type of tumor is not cancerous and occurs in the parotid gland.
Your healthcare team may share resources and websites to help you understand better what a Warthin tumor is, what to expect, and how it is treated. Learning about this condition is critical in preventing processes that can cause such a tumor. Often, nurses specialized in this field play a significant role in teaching patients about this condition.
For example, one key piece of advice they may give is to quit smoking. This is because smoking tobacco has been linked to the development of Warthin tumors.
