Salivary Gland Diseases

Salivary Gland Anatomy & Physiology - Gland Essentials

• Major Glands:
  • Parotid: Largest. Duct: Stensen's (opp. upper 2nd molar). Innervation: CN IX (parasymp), Symp.

    ⭐ Parotid gland is purely serous.

  • Submandibular: Mixed (mostly serous). Duct: Wharton's (sublingual caruncle). Innervation: CN VII (parasymp), Symp.
  • Sublingual: Smallest, mucous. Ducts: Bartholin's, Rivinus. Innervation: CN VII (parasymp), Symp.
• Minor Glands: Numerous, mainly mucous; oral mucosa (not gingiva, ant. hard palate).
• Saliva:
  • Composition: Water (99%), electrolytes, mucus, enzymes (amylase, lysozyme), IgA.
  • Functions: Digestion (starch), lubrication, protection, taste.
  • Daily volume: 0.5-1.5 L_

Sialadenitis & Infections - Glandular Battles

• Acute Bacterial Sialadenitis:
  • Organism: Staphylococcus aureus (most common).
  • Predisposing: Dehydration, post-op, sialoliths, immunosuppression.
  • Features: Sudden onset painful gland swelling, erythema, purulent discharge from duct.
  • Management:

• Chronic Sialadenitis: Causes: Recurrent inflammation, ductal obstruction (stones, strictures). Features: Intermittent, less painful swelling, often unilateral.
• Viral Sialadenitis (Mumps):
  • Agent: Paramyxovirus.
  • Features: Prodrome; bilateral (often), painful parotitis; fever.
  • Complications: Orchitis, oophoritis, pancreatitis, aseptic meningitis. 📌 Mumps Makes Parents Miserable.
• Sjögren's Syndrome: Autoimmune exocrinopathy.
  • Sicca symptoms: Xerostomia (dry mouth), xerophthalmia (dry eyes).
  • Diagnostic: Anti-Ro (SSA), Anti-La (SSB) antibodies; Schirmer's test < 5mm in 5 min; minor salivary gland biopsy.
  • Risk: ↑ MALT lymphoma (Non-Hodgkin).

⭐ Most common organism in acute suppurative sialadenitis is Staphylococcus aureus.

Sialolithiasis & Obstruction - Stony Troubles

• Definition: Salivary stones (calculi) causing ductal obstruction.

• Epidemiology: Most common: Submandibular gland (80-90%, Wharton's duct) due to viscous, alkaline saliva, uphill duct course, wider orifice.

  ⭐ Submandibular gland is the most common site for sialolithiasis (80-90%).

• Clinical Features: Colicky mealtime pain & swelling; recurrent sialadenitis.

• Diagnosis: Imaging - X-ray (often radiopaque), USG (first line), CT, Sialography (for radiolucent stones/ductal anatomy).

• Management:

  • Conservative: Hydration, sialogogues (e.g., lemon drops), gland massage, moist heat, NSAIDs.
  • Interventional: Sialendoscopy (diagnostic & therapeutic), lithotripsy (extracorporeal/intraductal), surgical removal (transoral ductal incision for distal stones; gland excision for intraglandular stones or recurrent disease).

Salivary Gland Tumors - Lumps & Bumps Galore

• General: Parotid (80% benign); Submandibular (50% benign); Sublingual/Minor (mostly malignant).
  • 📌 Parotid "Rule of 80s": 80% benign, 80% pleomorphic adenomas, 80% superficial lobe.
• Benign:
  • Pleomorphic Adenoma: Most common overall. Mixed. Slow growth. Malignant risk. Needs superficial parotidectomy (not enucleation).

    ⭐ Pleomorphic adenoma is the most common salivary gland tumor.

  • Warthin's Tumor: 2nd benign (parotid). Smokers, bilateral. "Hot spot" (Technetium).
• Malignant:
  • Mucoepidermoid Carcinoma: Most common malignant (overall & parotid).
  • Adenoid Cystic Carcinoma (ACC): Perineural invasion ('Swiss cheese'). Poor prognosis.
• Diagnosis: FNA; CT/MRI for extent.
• Management: Surgery (facial nerve preservation). Neck dissection (high-grade/N+). Radiotherapy (high-grade/ACC/margins+).
• Frey's Syndrome: Gustatory sweating post-parotidectomy. Minor's test.

Trauma, Cysts & Misc. - Glandular Glitches

• Mucoceles: Extravasation type, common on lower lip (minor gland trauma). Ranulas: Mucocele on floor of mouth (sublingual gland); 'plunging' if dissects mylohyoid. Mgt: Marsupialization, excision.
• Salivary Trauma: Ductal injury (esp. parotid) → sialocele. Repair if possible.
• Necrotizing Sialometaplasia: Benign, self-limiting, hard palate; mimics SCC. Ischemic cause.

⭐ A ranula is a mucocele specifically located on the floor of the mouth, arising from the sublingual gland.

High‑Yield Points - ⚡ Biggest Takeaways

• Pleomorphic adenoma is the most common benign salivary gland tumor, predominantly in the parotid.
• Mucoepidermoid carcinoma is the most common malignant salivary gland tumor overall.
• Warthin's tumor is benign, often bilateral (10%), strongly associated with smoking, and typically found in the parotid tail.
• Adenoid cystic carcinoma is notorious for perineural invasion and carries a guarded prognosis.
• Sialolithiasis (salivary stones) most commonly affects the submandibular gland and Wharton's duct.
• Frey's syndrome (gustatory sweating) is a known complication following parotidectomy.
• Sjögren's syndrome presents with xerostomia and keratoconjunctivitis sicca, increasing lymphoma risk.