Salivary Glands Flashcards
Salivary gland function
Produce saliva
- Functional unit = salivon
- Submandibular (70%)
- Parotid (25%)
- Sublingual (5%)
Function of saliva:
- Lubrication
- Digestion
- Protection (against infection)
Parotid anatomy
- Largest SG
- Triangular shape
- Wraps around angle of mandible
- Superficial to masseter muscle
Acini → Stenson’s duct → exits above upper 2nd molar → oral cavity
Structures that pass through gland:
- Facial nerve
- Retromadibular vein
- External carotid artery
Submandibular anatomy
- In posterior submandibular space
- Superficial lobe: superficial to mylohyoid muscle
- Deep lobe: deep to mylohyoid muscle
Acini → Wharton’s duct → exits floor of mouth
Sublingual anatomy
- Smallest SG
- In anterior submandibular space
- Almond-shaped
Acini → numerous submandibular ducts (‘duct of Rivinus’) → exit floor of mouth
Sialolithiasis (calculi)
Calculi in salivary glands or ducts
- 90% SMG (High viscosity secretions, Wharton’s duct = long upward course)
- 10% parotid
- 50% of cases have associated inflammation
Cause = stasis of flow
Factors that reduce flow:
- Dehydration
- Illness
- Medication
Presents:
- Swelling during eating
- Inflammation
Treatment:
- Surgical stone removal
Echogenic foci with posterior shadowing
Hypoechoic tubular structures (dilated ducts)
Acute sialadenitis
Inflammation of any salivary gland
- Usually affects 1 gland
Causes:
- Bacterial infection (85% parotid)
- Viral infection
Presents:
- Common in 50’s + 60’s
- Pain
- Swelling
- Erythema
- Dehydration
- Pus
- Fever
Treatment:
- Hydration + glandular massage
- Antibiotics
- US-guided drainage (abscess)
Diffusely enlarged hypoechoic heterogeneous gland
Hypervascular
Enlarged intraparotid lymph node or cervical lymphadenopathy
- *Abscess**
- Hypoechoic mass
- Posterior enhancement
- Internal debris
- No internal vascularity
Pleomorphic adenoma
- Most common benign SG tumour
- 60-90% parotid
- 10-30% SMG
Presents:
- Slow-growing mass
- Hard
- Painless
Treatment:
- Surgical resection
- *Well-defined hypoechoic homogeneous mass**
- Sometimes lobulated
Posterior enhancement
Hypovascular
- Differentials:*
- Warthin tumour*
- Mucoepidermoid cancer
Warthin’s tumour
- 2nd most common benign SG tumour
- Affects parotid only
- Risk factors = smoking + radiation
Presents:
- Painless swelling
- Men > women
- 6th decade
Treatment:
- Surgical resection
Oval well-defined hypoechoic mass
Multiple anechoic cystic areas
Hypervascular
- Differentials:*
- Pleomorphic adenoma*
- Mucoepidermoid cancer*
Mucoepidermoid carcinoma
- Most common SG malignant tumour
- 50% parotid
- Prognosis = good (low-grade), poor (high-grade)
Low grade: well-defined homogeneous hypoechoic mass
High-grade: poorly-defined heterogeneous hypoechoic mass
Local lymph nodes with metastatic features
- Differentials:*
- Pleomorphic adenoma*
- Warthin tumour*
