From the Guidelines
Investigations for salivary gland swelling should begin with imaging, specifically neck ultrasound, computed tomography (CT) with intravenous contrast, and/or magnetic resonance imaging (MRI) of the neck and primary site, as recommended by the American Society of Clinical Oncology (ASCO) guideline 1.
Initial Assessment
The initial assessment of salivary gland swelling involves a thorough clinical history and physical examination. This is crucial for identifying potential causes and guiding further investigations.
Imaging Modalities
Imaging plays a critical role in the evaluation of salivary gland swelling. The choice of imaging modality depends on the clinical presentation and the suspected underlying cause.
- Ultrasound is often recommended as the first-line imaging modality due to its accessibility, lack of radiation, and ability to distinguish between solid and cystic lesions.
- CT scanning with intravenous contrast provides comprehensive evaluation of the gland architecture and surrounding structures, and is particularly useful for assessing the extent of disease and potential involvement of adjacent structures.
- MRI is valuable for its ability to provide detailed anatomic delineation of the primary site and is the procedure of choice when perineural spread is suspected.
Tissue Biopsy
Tissue biopsy, either fine needle aspiration biopsy (FNAB) or core needle biopsy (CNB), is strongly recommended to support the distinction of salivary gland cancers from nonmalignant salivary lesions 1. This is essential for obtaining a definitive diagnosis and guiding further management.
Additional Investigations
Additional investigations may include:
- Sialography, which involves injecting contrast into the salivary ducts, can be useful for visualizing ductal abnormalities.
- Blood tests, including complete blood count, inflammatory markers (ESR, CRP), autoimmune antibodies (anti-SSA/Ro, anti-SSB/La), and amylase levels, help identify systemic causes.
- Microbiological cultures of any purulent discharge can identify infectious agents.
- Salivary flow rate measurements and minor salivary gland biopsy may be indicated in cases where autoimmune conditions are suspected.
- Core biopsy or open surgical biopsy might be necessary for definitive diagnosis in cases of persistent unexplained swelling.
Recent Guidelines
Recent guidelines from the American College of Radiology (ACR) recommend CT neck with IV contrast, MRI orbits, face, and neck without and with IV contrast, and FDG-PET/CT for initial staging and imaging of treated cancer of a major salivary gland 1. These recommendations highlight the importance of comprehensive imaging in the evaluation and management of salivary gland swelling.
From the Research
Investigations for Salivary Gland Swelling
Investigations for salivary gland swelling include:
- Imaging studies such as ultrasonography, computed tomography, or magnetic resonance sialography to evaluate the glandular tissue and excretory system 2, 3, 4
- Sialendoscopy to directly visualize the tissues and provide a diagnosis, and sometimes concurrently provide therapeutic intervention 2, 5
- Fine-needle aspiration biopsy to diagnose benign and malignant tumors 3
- Ultrasound examination, which is widely applied in non-neoplastic pathologies and can obtain adequate images without the use of ionizing radiation or complex instrumentation 6, 4
Diagnostic Considerations
When choosing an imaging procedure, consideration should be given to reliability, side effects, accessibility, and costs 4
- Ultrasound and magnetic resonance imaging are preferred because they can investigate almost all inflammatory diseases of the large salivary glands with accurate results, without exposing the patient to radiation 4
- Sialendoscopy can be used to drive treatment plans and sometimes concurrently provide therapeutic intervention, including endoscopic intervention, Botox, and gland-preserving surgical techniques 5