EN4.35 | Salivary Gland Diseases — Summary & Reflection

KEY TAKEAWAYS

Salivary gland diseases span a wide clinical spectrum. The three major salivary glands differ in their anatomy, secretory properties, and disease predispositions: the parotid (serous, with intraglandular lymph nodes and the facial nerve traversing it) is the site of most salivary neoplasms; the submandibular gland (mucous-rich, long duct against gravity) is the site of 80% of calculi.

Inflammatory disease (acute suppurative sialadenitis, mumps parotitis) is treated with antibiotics, hydration, and — if an abscess forms — surgical drainage. Obstructive disease (sialolithiasis) presents classically with mealtime swelling and pain; submandibular calculi (80% radio-opaque) are treated by duct incision, sialoendoscopy, or gland excision. Neoplastic disease requires FNAC (never incisional biopsy) — 80% of parotid tumours are benign; the commonest benign tumour is pleomorphic adenoma (treat with superficial parotidectomy, never enucleation); the commonest malignant salivary tumour is mucoepidermoid carcinoma; adenoid cystic carcinoma spreads perineurally. Systemic causes include Sjögren's syndrome (anti-Ro/La antibodies, sicca complex, lip biopsy confirmatory), sarcoidosis (Heerfordt syndrome), and HIV-associated lymphoepithelial cysts.

Key investigations: ultrasound (first-line), plain X-ray (calculi), FNAC (tissue diagnosis), MRI (soft tissue + perineural spread), serology (Sjögren's workup). Red flags for malignancy: rapid growth, pain, hard fixed mass, facial palsy, lymphadenopathy.

REFLECT

Think about a patient you might see in a busy general outpatient clinic presenting with a slowly enlarging painless parotid swelling. How would you systematically assess this patient to distinguish a pleomorphic adenoma from an early parotid malignancy? What findings in the history and examination would move you from a reassuring to a concerned clinical posture, and at what point would you escalate to specialist referral? Consider also the importance of not offering an incisional biopsy when the patient (or a well-meaning colleague) presses for one — how would you explain to the patient why FNAC is the correct approach and why the biopsy they are requesting could actually harm them?