Oral cavity and salivary gland

Question 1

Cleft lip and palate

Answer 1

Full thickness defect of lip or palate

• due to failure of facial prominence to fuse
• during early pregnancy, facial prominences (one from superior, two from the sides, and two from inferior) grow and fuse together to form the face
• cleft lip and palate usually occur together –> isolated cleft lip or palate is less common

Question 2

Aphthous ulcer

Answer 2

Painful, superficial ulceration of the oral mucosa

• arises in relation to stress and resolves spontaneously, but often recurs
• characterized by a grayish base (granulation tissue) surrounded by erythema

Question 3

Behcet syndrome

Answer 3

Recurrent aphthous ulcers, genital ulcers, and uveitis

• due to immune complex vasculitis involving small vessels
• can be seen after viral infection, but etiology is unknown

Question 4

Oral herpes

Answer 4

Vesicles involving oral mucosa that rupture, resulting in shallow, painful, red ulcers

• usually due to HSV1
• primary infection occurs in childhood, lesions heal but virus remains dormant in ganglia of the trigeminal nerve
• stress and sunlight cause reactivation of the virus, leading to vesicles that often arise on the lips (cold sore)

Question 5

Squamous cell carcinoma

Answer 5

Malignant neoplasm of squamous cells lining the oral mucosa

• tobacco and alcohol are major risk factors
• floor of mouth is the most common location

Oral leukoplakia and erythroplakia are precursor lesions
- leukoplakia –> white plaque that cannot be scraped away; often represents squamous cell dysplasia

Leukoplakia is distinct from oral candidiasis (thrush) and hairy leukoplakia

• Oral candidiasis –> white deposit on the tongue, which is easily scraped away; usually seen in immunocompromised states
• hairy leukoplakia –> a white, rough (hairy) patch that arises on the lateral tongue; usually seen in immunocompromised individuals (AIDS) and is due to EBV induced squamous cell hyperplasia, not premalignant

Erythroplakia (red plaque) –> represents vascularized luekoplakia and is highly suggestive of sqaumous cell dysplasia

Erythroplakia and leukoplakia are often biopsied to rule out carcinoma

Question 6

Salivary gland - basic principles

Answer 6

Salivary glands are exocrine glands that secrete saliva
- divided into major = parotid, submandibular, and sublingual glands, and minor = hundreds of microscopic glands distributed throughout the oral mucosa

Question 7

Mumps

Answer 7

Infection with mumps virus resulting in bilateral inflamed parotid glands

• orchitis, pancreatitis and aseptic meningitis may also be present
• serum amylase is increased due to salivary gland or pancreatic involvement
• orchitis carries risk of sterility, especially in teenagers

Question 8

Sialadenitis

Answer 8

Inflammation of the salivary gland

- most commonly due to an obstructing stone (sialolithiasis) leading to staph aureus infection –> usually unilateral

Question 9

Pleomorphic adenoma

Answer 9

Benign tumor composed of stromal (e.g. cartilage) and epithelial tissue (e.g. glands); most common tumor of the salivary gland

• usually arises in parotid –> presents as a mobile, painless, circumscribed mass at the angle of the jaw
• high rate of recurrence –> extension of small islands of tumor though tumor capsule often leads to incomplete resection
• rarely may transform into carcinoma –> presents with signs of facial nerve damage (facial nerve runs through parotid gland)

Question 10

Warthin tumor

Answer 10

Benign cystic tumor with abundant lymphocytes and germinal centers (lymph node-like stroma)

• second most common tumor of the salivary gland
• almost always arises in the parotid

Question 11

Mucoepidermoid carcinoma

Answer 11

Malignant tumor composed of mucinous and squamous cells –> most common malignant tumor of the salivary gland
- usually arises in the parotid –> commonly involves the facial nerve