Sialoadenosis
Sialoadenosis is a radiological finding that indicates diffuse, bilateral, noninflammatory, nonneoplastic enlargement of the major salivary glands. This condition represents an abnormal enlargement of salivary tissue without inflammation or tumor development. It is typically identified incidentally during imaging studies performed for other reasons. This article explains the radiological features, underlying causes, and clinical significance of sialoadenosis to help patients understand this diagnosis.
What Is Sialoadenosis?
Sialoadenosis refers to a diffuse, bilateral, noninflammatory, nonneoplastic enlargement of the major salivary glands. In simpler terms, it means your salivary glands have become larger than normal, but not due to inflammation or cancer.
This enlargement typically affects the parotid glands (located in front of your ears), but occasionally can involve the submandibular glands (beneath your jawline) and rarely the minor salivary glands scattered throughout your mouth. The condition is characterized by a bilateral, usually symmetrical swelling that is often painless, though some patients may experience tenderness.
How Sialoadenosis Appears on Imaging
When your doctor orders imaging tests for sialoadenosis, several findings may be visible depending on the imaging method used:
Ultrasound Findings
On ultrasound examination, sialoadenosis typically shows a hyperechoic (appearing brighter) gland with no focal lesions. Ultrasound is often the first imaging test ordered because salivary glands are superficial structures that are easily accessible with this technique.
The salivary glands’ superficial location makes them particularly suitable for ultrasound examination, especially when using high-frequency probes designed for small parts. This allows for good visualization without exposure to radiation.
CT Scan Findings
CT scanning initially reveals diffuse glandular enlargement. As the condition becomes more chronic, fatty infiltration of the gland may be observed.
CT images typically show enlarged parotid glands bilaterally with no signs of ductal dilation, stones, obstruction, or inflammation. This helps distinguish sialoadenosis from other salivary gland disorders.
MRI and Other Advanced Imaging
Magnetic resonance imaging (MRI) is of limited utility in diagnosing sialoadenosis or sialadenitis. It doesn’t allow evaluation of the ductal system and isn’t helpful in defining calcifications. However, MRI excels at soft tissue definition and can be valuable if there’s a concern about possible tumor.
Sialography, a specialized imaging technique that uses contrast material to visualize the salivary ducts, may be useful for later-stage diagnosis. It may show a thin ductal system due to compression from swelling.
Common Causes of Sialoadenosis
Sialoadenosis doesn’t occur on its own but is typically associated with underlying conditions:
This condition often occurs in the setting of:
- Endocrine disorders (diabetes, hypothyroidism)
- Nutritional disorders (anorexia/bulimia, vitamin deficiencies)
- Metabolic disorders (obesity, liver cirrhosis)
- Medications
Differential Diagnosis
When radiologists see enlarged salivary glands on imaging, they need to differentiate sialoadenosis from other conditions:
Bilateral painless and prolonged parotid swelling without signs of excretory abnormalities may indicate sialoadenosis. It’s important to distinguish this from other causes of chronic diffuse swelling such as Sjögren’s syndrome, HIV sialadenitis, and radiation-induced sialadenitis, which are often associated with “dry mouth” symptoms.
Imaging is helpful in distinguishing sialoadenosis from other conditions like acute bacterial suppurative sialadenitis (which may show an abscess), obstructive sialadenitis (which shows stones or strictures), or immunoglobulin G4-related sialadenitis
Treatment Approach
The treatment of sialoadenosis primarily involves management of the underlying condition. For example, if diabetes is the cause, better glucose control may help. If medications are causing the problem, your doctor might consider alternatives.
This finding often indicates an underlying metabolic or systemic condition that requires attention. The salivary gland enlargement itself is usually a symptom rather than the primary concern. Many patients are surprised to learn that their salivary gland changes may be connected to conditions affecting other parts of their body, such as liver disease or diabetes.
When to Be Concerned
Sialoadenosis itself is a benign condition, but the underlying causes may require medical attention. Contact your doctor if you experience:
- Rapid increase in swelling
- Severe pain
- Difficulty swallowing or breathing
- Fever accompanying the swelling
- One-sided rather than bilateral swelling
Conclusion
Sialoadenosis indicates non-inflammatory, non-cancerous enlargement of your salivary glands, usually related to an underlying systemic condition. The imaging findings primarily show enlarged glands without inflammation or obstruction. While the condition itself is benign, addressing the underlying cause is essential for proper management. With proper management, many patients see improvement in their salivary gland enlargement over time.
References
- https://www.ncbi.nlm.nih.gov/books/NBK562211/
- https://medicine.uiowa.edu/iowaprotocols/sialosis-or-sialadenosis-salivary-glands
- https://radiopaedia.org/articles/sialosis-1?lang=us