Sialolithiasis of Parotid Gland

Parotid sialolithiasis is calculus formation in the parotid gland or the Stensen duct. It accounts for 10 to 20 percent of salivary stones; the stones are usually smaller, softer and less often radiopaque than submandibular stones.

• The saliva is serous and low in calcium, so stones form less often.
• Dehydration, diuretics, anticholinergic drugs, Sjogren syndrome and poor oral hygiene contribute.
• Stones may sit at the duct opening, at the masseter bend or inside the gland.

Pain and swelling in the cheek and in front of the ear during meals, settling slowly afterwards, with intermittent fever and bad taste when infected.

• A stone may be felt in the duct along the cheek, and pus may emerge from the opening opposite the second upper molar.
• Differential diagnosis: mumps, parotitis, parotid tumour, lymphadenitis, dental disease, temporomandibular joint pain, Sjogren syndrome, HIV related parotid cysts, tuberculosis, masseter hypertrophy.
• Complications: acute parotitis, abscess, duct stricture, gland atrophy, facial nerve palsy in severe infection.

Ultrasound is the first investigation, with sialendoscopy for confirmation.

• Ultrasound; CT without contrast for small or radiolucent stones.
• Culture of expressed pus; full blood count and CRP in infection.
• Sjogren antibodies and HIV test in bilateral or recurrent disease.

Stimulate flow, treat infection and remove the stone by gland sparing methods.

• Supportive: hydration, sour stimulants, warm compresses, gland massage toward the duct, oral hygiene, avoid drying drugs.
• Pharmacological: ibuprofen 400 mg three times daily with food; amoxicillin clavulanate 625 mg three times daily for 7 days or flucloxacillin 500 mg four times daily if infection; clindamycin 300 mg four times daily in penicillin allergy.
• Procedures: sialendoscopy with basket retrieval or laser fragmentation (first choice for most stones); intraoral duct cutdown for distal stones; extracorporeal shock wave lithotripsy; superficial parotidectomy with facial nerve preservation only as a last resort.
• Special groups: children, sialendoscopy and weight based antibiotics; pregnancy, conservative measures with surgery deferred; Sjogren syndrome, rheumatology care.
• Red flags: facial weakness, fixed hard mass, high fever with swelling, trismus, airway involvement, weight loss.
• Follow-up: review at 4 to 6 weeks with ultrasound; recurrent stones need repeat endoscopy.