by Vidya Sankar, DMD, MHS, Tufts University, Associate Professor, Director, Division of Oral Medicine, Department of Diagnostic Sciences
Because the clinical presentation of Sjögren’s varies a great deal and there is no ONE test that can diagnose the disease, multiple tests are used in the diagnosis of Sjögren’s. These include tests measuring salivary and lacrimal gland function (salivary and tear flow rates), but low flow rates can also be caused by medications, other systemic illnesses, caffeine intake, the time of day the tests are obtained, as well as states of dehydration. Blood test such as anti-SSA autoantibodies, are positive in only 30-70% of Sjögren’s patients and are not considered totally specific to the disease since they are found in 30% of lupus patients. When the diagnosis is not clear, tissue studies (biopsies) such as the salivary gland biopsy (either parotid gland or minor salivary glands) are extremely helpful in diagnosing the disease. The biopsy looks for signs of inflammation and cells that respond to inflammation that build up within the exocrine glands (salivary and lacrimal). As inflammation increases, it obliterates and destroys normal functioning gland tissue. If the tissue cannot function or is destroyed, saliva and tears cannot be produced. Biopsies may also be a useful tool in assessing patient’s responses to treatment. Many research studies look for changes in the minor salivary glands such as a reduction in inflammation to determine if the medication is working.
You have two pairs of major salivary glands, the parotid (in front of the ears/cheek region) and sub-mandibular (below the jaws/neck region) glands. Combined, these salivary glands produce about 90% of your saliva. In addition to those major salivary glands, there are about 750 minor salivary glands distributed throughout the mouth. They can be found just about anywhere within the oral cavity but are abundant inside the lips, cheeks and on the palate (roof of the mouth). Although there are so many of these minor glands, they only produce about 10% of total saliva. Biopsy of the major salivary glands, such as the parotid gland, can be tricky due to the location of nerves and blood vessels within and throughout the glands as well as cosmetic concerns (biopsies are done through the skin of the face/neck). While the same pathological findings are seen in the lacrimal glands, their proximity to the eye makes it impractical to biopsy these glands. The minor salivary glands are very easy to access as they are abundant along the inside of the lower lip, and the biopsy is done within the mouth, so esthetics are not an issue. For these reasons, the minor salivary glands are frequently selected for biopsy.
The minor gland biopsy can be done in an out- patient setting under local anesthesia (xylocaine) administered directly to the area being biopsied. A small incision is made, less than 1⁄2 an inch long, and around 4 of these glands (that are about the size of a pepper corn) are removed. The site is usually closed with a couple stitches and the procedure is over with- in 10-15 minutes. Patients are free to resume routine activities immediately but are cautioned about eating/chewing since they might bite their lip and not be aware of it due to the numbness. The numbness usually lasts for a couple hours. Once the anesthesia wears off, routine over the counter pain medications such as ibuprofen or acetaminophen are sufficient to manage the post-operative pain. The biopsy site heals quickly with little to no scarring. If scars do develop, they are inside of the mouth so it is of little to no esthetic concern. Side effects include minimal post-operative bleeding, which is usually controlled by the stitches, as well as placing gauze pads with a little pressure. The bleeding typically lasts for a few minutes up to an hour. Swelling can occur- reaching its peak 2-3 days after the procedure and then resolves. Infections are rare. Of course, there might be some side effects like prolonged numbness or tingling in the area biopsied. This has been reported in about 5% of patients. A majority of the patients that experience this regain normal sensations within several weeks to months. A number of medications- both prescription and herbal may have an impact on bleeding and ability to heal. Therefore, it is important to tell your doctor about which medications you are taking, so that the appropriate measures can be taken to minimize these events.
Biopsies should be performed by individuals who are familiar with the lip biopsy procedures, this includes Oral Medicine specialists, and certain Oral Surgeons and Otolaryngologists (ENTs). Once the specimen is obtained, the tissue should be sent to an oral pathologist who are familiar with the specific inflammatory characteristics and patterns associated with Sjögren’s for diagnosis.
The minor gland lip biopsy is a safe procedure and can be instrumental when it comes to diagnosing Sjögren’s and helpful in determining if patients are responding to therapy. Understanding the role of the biopsy in diagnosis and what to expect when undergoing the procedure may help patients seek out qualified individuals when making the determination to have the biopsy.
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