Salivary Gland Pathology MCQ

The salivary glands produce their own spectrum of disease, from the trivial blocked duct to autoimmune dry mouth and to benign and malignant tumors. A few clues carry most of the diagnoses: mealtime swelling of a gland means an obstructing stone, dry mouth plus dry eyes means Sjogren syndrome, and the smaller the gland the more likely a tumor in it is malignant. A firm swelling on the palate is not always an abscess, and that distinction can matter a great deal.

Mucus Cysts and Obstruction

• The mucocele is the most common, classically on the lower lip: trauma severs a minor salivary gland duct and mucus spills into the tissue (a mucus extravasation lesion), giving a bluish, fluctuant swelling that may rupture and recur.
• The ranula is a mucus lesion of the floor of the mouth arising from the sublingual gland; a plunging ranula dips below the mylohyoid into the neck.
• Sialolithiasis (a salivary stone) most often affects the submandibular gland and its duct (Wharton duct), because that secretion is more mucous and the duct runs upward against gravity; the classic symptom is painful swelling at mealtimes.
• Management follows the cause: a mucocele is excised together with the feeding minor gland (or it recurs), and a stone is removed (by milking, sialendoscopy, or surgery) with measures to restore salivary flow.

Salivary Gland Infection and Inflammation

• Acute bacterial sialadenitis (often Staphylococcus aureus) strikes the dehydrated, debilitated, or post-operative patient with reduced salivary flow: a painful, swollen, tender gland with pus expressible from the duct.
• Mumps is a viral (paramyxovirus) cause of bilateral parotid swelling, now uncommon because of MMR vaccination.
• Necrotizing sialometaplasia is a benign, self-healing ulcer of the palate (often after trauma or ischemia) that clinically and microscopically mimics malignancy, so it must be recognized to avoid overtreatment.
• Management of acute bacterial sialadenitis is rehydration, gland massage, sialagogues to stimulate flow, and antibiotics; viral mumps is supportive.

Sjogren Syndrome and Xerostomia

• Sjogren syndrome is autoimmune destruction of the salivary and lacrimal glands, producing dry mouth (xerostomia) and dry eyes (keratoconjunctivitis sicca); primary Sjogren occurs alone, while secondary Sjogren accompanies another autoimmune disease such as rheumatoid arthritis or lupus.
• It is associated with anti-SSA (Ro) and anti-SSB (La) antibodies, and it carries an increased risk of lymphoma, so persistent gland enlargement is watched.
• The oral consequences are major: rampant (especially cervical and root) caries, candidiasis, difficulty eating and speaking, and a higher risk of mucosal infection, all from the loss of saliva's buffering, clearance, and antimicrobial action.
• Xerostomia also results from medications (especially anticholinergic drugs), head and neck radiation, and dehydration; management includes saliva substitutes, sialagogues, meticulous fluoride and caries prevention, and hydration.

Salivary Gland Tumors

• The pleomorphic adenoma is the most common salivary gland tumor: a benign, slow-growing, painless mass usually in the parotid; it can recur if incompletely removed and rarely undergoes malignant transformation.
• The Warthin tumor is a benign parotid tumor that can be bilateral, classically in older male smokers.
• The mucoepidermoid carcinoma is the most common salivary malignancy, affecting the parotid and the minor glands (notably the palate); the adenoid cystic carcinoma is known for perineural invasion, pain, and a relentless course with late distant spread.
• Two rules guide suspicion: the smaller the gland, the more likely a tumor in it is malignant (so minor-gland and submandibular tumors are more often malignant than parotid tumors), and the facial nerve runs through the parotid, so facial weakness with a parotid mass is an ominous sign.