Papillary Cystadenoma Lymphomatosum

Warthin’s tumor, Warthin tumour, cystadenolymphoma, adenolymphoma, monomorphic adenoma

Papillary cystadenoma lymphomatosum is a non-cancerous growth that most commonly develops in the salivary glands near the ear. Despite its complex name, this slow-growing tumor is the second most frequent benign tumor of these glands and rarely causes serious problems.

Table of contents

• What is papillary cystadenoma lymphomatosum
• Where the tumor develops
• Who is affected
• What causes this condition
• Signs and symptoms
• How doctors identify the tumor
• Treatment options
• What to expect after treatment

What is papillary cystadenoma lymphomatosum

Papillary cystadenoma lymphomatosum, more commonly known as Warthin’s tumor, is a non-cancerous growth that develops in the salivary glands. It was named after pathologist Aldred Scott Warthin, who first described two cases in 1929.^[1] This type of tumor is also called cystadenolymphoma or adenolymphoma.^[3]

The tumor contains fluid-filled spaces and is characterized by the presence of abundant immune cells called lymphocytes and structures that resemble lymph nodes. Under the microscope, doctors can identify it by its unique features: cystic spaces surrounded by two uniform rows of special cells called oncocytes, which are epithelial cells with abundant, granular material inside them.^[1]

• Parotid gland
• Salivary glands

Where the tumor develops

Warthin’s tumor is almost exclusively found in the parotid gland, which is the largest salivary gland located near the ear and angle of the jaw. In fact, it is the only tumor that is virtually restricted to the parotid gland.^[1] The tumor usually appears in the tail portion of the parotid gland near the angle of the mandible (lower jaw bone).^[1]

While rare, papillary cystadenoma lymphomatosum can occasionally develop outside the parotid gland. These uncommon locations include the lymph nodes near the parotid, the nasopharynx (upper part of the throat behind the nose), the eyelid, and the oral cavity (mouth).^[3] When it occurs in the minor salivary glands of the mouth, it manifests as a slow-growing tumor that feels soft or fluctuant when touched because of its cystic nature.^[2]

One unique characteristic of this tumor is that it can appear in both parotid glands at the same time, which doctors call bilateral occurrence. This happens in 5 to 14 percent of cases, although the two masses usually develop at different times.^[1][4]

Who is affected

Warthin’s tumor is the second most common benign tumor of the salivary glands, after another type called pleomorphic adenoma. It accounts for about 2 to 15 percent of all tumors affecting the parotid gland.^[3][4] Some sources describe it as the most common “monomorphic” adenoma of the major salivary glands.^[3]

This condition primarily affects older individuals, typically appearing when people are in their 60s or 70s. The peak incidence occurs in the sixth decade of life for women and the seventh decade for men.^[1][3] While it occasionally occurs in young patients, this is uncommon.^[3]

There has traditionally been a slight male predominance for this condition according to recent studies, although reports indicate that the difference between men and women is declining.^[1][3]

What causes this condition

The exact cause of papillary cystadenoma lymphomatosum remains uncertain and continues to be debated among medical experts.^[3] Several theories have been proposed over the years. Some researchers believe the tumor arises from cells that became trapped in lymph nodes adjacent to the parotid gland or within the gland itself.^[3]

What is clear is that there is a strong association with cigarette smoking. Warthin’s tumor is the only benign tumor of the salivary glands that has been linked to smoking.^[3] People who smoke are at eight times greater risk of developing this tumor compared to the general population.^[1]

Other factors that have been suggested to play a role include Epstein Barr virus infection, autoimmune disease, ionizing radiation, and chronic inflammation.^[3] However, many questions remain about why this tumor shows a preference for affecting men and why tobacco should predominantly affect the parotid gland rather than the minor salivary glands inside the mouth.^[3]

Signs and symptoms

The tumor typically grows slowly and is painless. It usually appears as a mass near the angle of the mandible where the tail of the parotid gland is located.^[1] Because of its cystic structure containing fluid, the tumor may feel soft or fluctuant when a doctor presses on it.^[2]

Patients may notice a gradually enlarging lump in the area in front of or below the ear. The growth develops over months or even years. In some cases, patients may not experience any symptoms at all, and the tumor is discovered during examination for other reasons.^[2]

It’s important to note that Warthin’s tumor is highly unlikely to become cancerous. Malignant transformation is extremely rare and accounts for only 0.3 percent of cases.^[3]

How doctors identify the tumor

Doctors use several methods to diagnose papillary cystadenoma lymphomatosum. Imaging techniques such as ultrasound, computed tomography (CT) scans, or magnetic resonance imaging (MRI) help visualize the tumor’s location and structure.^[7]

To confirm the diagnosis, a biopsy may be performed. This involves taking a small sample of tissue from the tumor for examination under a microscope.^[7] The microscopic appearance of this tumor is quite distinctive and helps doctors differentiate it from other types of growths.

Under the microscope, doctors look for cystic spaces surrounded by two uniform rows of oncocytes. These spaces have epithelium with characteristic infoldings that project into them, described as papillary infoldings. Additionally, the tissue shows a lymphoid component with structures called germinal centers.^[1]

Other conditions that doctors must consider and rule out include sebaceous lymphadenoma and oncocytoma, which can have some similar features.^[1]

Treatment options

The treatment of choice for papillary cystadenoma lymphomatosum is complete surgical removal with wide tumor-free margins.^[2] Most of these tumors are treated with a surgical procedure called parotidectomy, which involves removing part or all of the parotid gland.^[1]

The specific type of surgery depends on the tumor’s location and size. The vast majority of cases are treated with subtotal parotidectomy, where most but not all of the gland is removed. In a small percentage of cases, total parotidectomy may be necessary, where the entire gland is removed.^[10]

During surgery, doctors make every effort to preserve the facial nerve, which runs through the parotid gland and controls the muscles of facial expression. Preservation of this nerve is critical to maintain normal facial movement and appearance.^[10]

What to expect after treatment

The outlook for people with Warthin’s tumor is excellent. Unlike pleomorphic adenoma (another type of salivary gland tumor), papillary cystadenoma lymphomatosum rarely comes back after surgical removal.^[1][4] With proper surgical treatment, recurrence is uncommon.^[4]

However, surgery on the parotid gland does carry some risks of complications. The most frequent complication is facial nerve dysfunction, which can affect the ability to move certain facial muscles. When this occurs, the marginal mandibular branch of the facial nerve, which controls the lower lip, is most commonly affected.^[10]

Another potential late complication is Frey’s syndrome, a condition where sweating occurs on the cheek during eating. This happens because nerve fibers that normally control salivary gland function reconnect inappropriately with sweat glands in the skin after surgery.^[10]

Despite these possible complications, surgical removal with preservation of the facial nerve remains the treatment of choice, and most patients do well with no recurrence of the tumor after long-term follow-up.^[10]