Parotitis Workup

• Chemical analysis of saliva

  • Anti-SS-A, anti-SS-B, and rheumatoid factor may be present in autoimmune diseases. Saliva may be cultured, which is helpful, and it may be analyzed chemically, which is rarely helpful.
  • Most laboratories cannot perform useful tests on saliva. Dental researchers had hopes for several decades that analysis of saliva would be of diagnostic importance. Saliva has such wide variations in composition that analysis has produced little of diagnostic value.

• CT scanning and MRI with gadolinium enhancement

  • These studies may be used to determine the size, shape, and some qualities of neoplasms or swelling within the gland.
  • Either method reliably differentiates between solid masses, cystic lesions, and diffuse involvement of the gland.
• Sialography

  • Sialography is used to demonstrate the anatomy of the drainage system and is a very useful test. Injury to the ducts or acini is demonstrated with this study. Many radiologists no longer perform the test, which is unfortunate. Most dentists can perform sialography in the office. The otolaryngologist can cannulate the duct and inject the dye in the radiology suite.
  • A scout radiograph should be made to rule out radiopaque stones or calcification within the gland.
  • A special cannula or #90 polyethylene tubing is inserted into the duct, and iodinated oil such as Ultravist (iopromide) oily Dionosil is injected into the ductal system.
  • The normal ducts can accommodate 0.50-0.75 mL without discomfort. The authors inject until the patient reports discomfort and then posteroanterior and lateral radiographs are obtained.
  • The study is repeated 5 minutes later. Usually, all of the contrast media has been evacuated.
  • The normal ductal system looks like a deciduous tree in winter. In sialectasis, the radiographs may have the appearance of a tree with scattered leaves (as seen in the image below). The ductal system may be dilated and demonstrate numerous small strictures giving the appearance of "sausaging." Sialogram of patient with sialectasis. Notice the appearance of a tree with leaves.
• Ultrasonography is much easier to perform than sialography and seems to be replacing sialography in many institutions. It demonstrates solid masses or fluid collections within the gland. It also can detect hypoechoic areas that correspond to punctate sialectasis by sialography. It is not as sensitive as sialography, but this is probably not clinically significant.

Interventional sialoendoscopy

This technique is growing in popularity and availability and seems to be the best method of treatment.^[12] The duct is anesthetized and dilated to insert a telescope for inspection of the large ducts. A working channel in the telescope permits irrigation, suction, and insertion of forceps, wire loop, or even laser energy via a glass fiber to remove the calculi. The clinician has much more information as to the condition of the duct system. This instrument is useful for the assessment and treatment of several inflammatory disorders of the gland.

Advances in the management of chronic sialoadenitis include endoscopic-assisted approaches. Initially, salivary endoscopy is performed to identify any stones. If none is located, ultrasonography or CT imaging is recommended. The endoscopic-assisted management technique is a safe and often effective means of evaluating the anatomy, administering various irrigations (eg, saline, antibiotics, steroids), performing sialodochoplasty, removing stones, and placing stents. In Europe, this technique is mainly performed with the patient under local anesthesia, but in the United States, general anesthesia is preferred since more aggressive procedures can be readily performed at a single setting with the patient under anesthesia if the endoscopic approach is not successful. Studies suggest a high rate of symptom control, and future studies are underway to further address a possibly larger role for this technique.^{[13, 14, 15, 16]}

Incisional biopsy

Under local anesthesia, a biopsy of the tail of the gland may be obtained by an experienced surgeon without injury to the facial nerve. Fine-needle aspiration biopsy frequently is diagnostic for tumors and may be helpful to identify cell types and to obtain material for cultures when the clinical picture suggests infection. Excisional biopsy of a labial minor salivary gland may be diagnostic when the clinical picture suggests Sjögren syndrome.

Excision of parotid tissue is infrequently used for diagnosis. When removed for acute infection, acute necrosis of the glandular elements is observed. Autoimmune parotitis occasionally progresses to lymphoma, and biopsy is performed when suspected. Invasion by lymphocytes and destruction of the glandular elements are observed.