Introduction

Warthin's tumor, also known as papillary cystadenoma lymphomatosum, is a benign cystic tumor of the salivary glands containing abundant lymphocytes and germinal centers (lymph node-like stroma).

OR

Warthin's tumor is an adenoma composed of bilayered columnar and basaloid oncocytic epithelium that forms multiple cysts with numerous papillae, accompanied by a proliferation of follicle-containing lymphoid tissue

It is named for pathologist Aldred Scott Warthin, who described two cases in 1929

Warthin’s tumor is second most common benign salivary gland tumor

Epidemiology

• Warthin tumor is the most common ‘monomorphic’ adenoma of the major salivary glands.
• It accounts for about 2% to 15% of all parotid tumors
• M>F
• Most common site Tail of parotid

Causes

• The exact underlying cause of Warthin tumor is currently unknown.
• However, smoking is thought to increase the risk of developing the tumor.
• Some studies suggest that radiation exposure and autoimmune disorders may also be associated with Warthin tumor

Signs and Symptoms

• Firm, usually painless swelling in one of the salivary glands (in front of the ears, under the chin, or on the floor of the mouth).
• Swelling can progress at varying rates depending on the underlying cause.
• Slow swelling usually indicates a benign tumor, while rapid swelling is more likely to indicate a malignant tumor or infection.
• Difficulty moving one side of the face, known as facial nerve palsy.
• This can signal a malignant and advanced tumor, primarily in the parotid gland.

Gross Pathology

• Encapsulated
• Smooth/lobulated surface
• Soft, fluctuant, compressible
• Cystic spaces of variable size, with viscous fluid, shaggy epithelium
• The size of a Warthin tumor can vary from a few millimeters to several centimeters •Solid areas with white nodules representing lymphoid follicles

Histology

• Thin capsules usually sharply demarcate tumor from surrounding parenchyma.
• Cystic spaces are lined by a papillary proliferation of bilayered, oncocytic epithelium whose supporting stroma is composed largely of lymphoid tissue
• Dense lymphoid stroma with double layer of epithelial cells resting on the stroma.
• The cystic spaces are present which are narrowed by polypoid projections.
• Basal cell layer is not continuous and is interrupted in places .
• The oncocytic columnar cells palisade on the surface.
• There is no myoepithelial component present in tumor.
• Occasional features include cilia, squamous metaplasia with necrosis, mast cells, dendritic cells and sebaceous cells.

Diagnosis

• X-rays of the salivary gland (called a sialogram) to look for a tumor
• Ultrasound, CT scan or MRI to confirm that there is a growth, and to see if it has spread to lymph nodes in the neck
• Salivary gland biopsy or fine needle aspiration to determine whether the tumor is benign or malignant
• Sialendoscopy, a minimally invasive outpatient procedure, used to identify small tumors that may otherwise go unnoticed and progress to later-stage cancer
• Positron emission tomography (PET) scans may be of value in assessing malignant tumors, with attention to metastatic adenopathy and distant metastases

Treatment

• The treatment involves a surgical procedure to remove the neoplastic lesion.
• This procedure is relatively easy due to the favorable, superficial location of the tumor.
• The exact method of tumor removal depends on its precise location. In many cases, a so-called Parotidectomy is performed, which involves the surgical removal of a part or all of the parotid gland.
• This procedure minimizes the risk of relapse.

Prognosis

• Due to the benign nature of Warthin's tumor, the overall prognosis is good
• Possible complications result from the risk of damage to the facial nerve during surgery (this nerve courses through the parotid).