Diseases of the Oral Cavity and Salivary Glands Practice Questions

Q: What is the most common malignant tumor of the salivary glands?

Mucoepidermoid carcinoma. **Explanation:** **Mucoepidermoid Carcinoma (MEC)** is the most common malignant tumor of the salivary glands in both adults and children. It most frequently involves the **parotid gland**, though it is also the most common malignancy of minor salivary glands. Histologically, it is characterized by a mixture of mucus-secreting cells, squamous (epidermoid) cells, and intermediate cells. **Analysis of Options:** * **Pleomorphic Adenoma (Option A):** This is the most common **benign** tumor of the salivary glands overall. While it is the most frequent salivary neoplasm, the question specifically asks for a **malignant** tumor. * **Warthin Tumor (Option B):** Also known as Adenolymphoma, this is the second most common benign tumor. It is strongly associated with smoking and typically occurs in the tail of the parotid gland in older males. * **Adenoid Cystic Carcinoma (Option C):** This is the most common malignant tumor of the **submandibular and minor salivary glands** (specifically the palate). It is notorious for **perineural invasion**, leading to pain and "skip lesions." **High-Yield Clinical Pearls for NEET-PG:** * **Rule of 80s (Parotid Tumors):** 80% are in the parotid, 80% are benign, 80% are Pleomorphic Adenoma, and 80% occur in the superficial lobe. * **Small Gland Rule:** The smaller the salivary gland, the higher the chance of a tumor being malignant (e.g., Sublingual gland tumors are ~80% malignant). * **Most common site for MEC:** Parotid gland. * **Most common site for Adenoid Cystic Carcinoma:** Minor salivary glands (Palate).

Q: Parotid fatty change is a sign of?

Alcoholism. **Explanation:** The correct answer is **Alcoholism**. **Medical Concept:** Parotid fatty change, often presenting clinically as **Sialadenosis** (Sialosis), is a non-inflammatory, non-neoplastic, bilateral enlargement of the parotid glands. In chronic alcoholism, the underlying mechanism involves autonomic neuropathy and metabolic disturbances. This leads to the accumulation of intracytoplasmic lipid droplets within the acinar cells and the replacement of glandular parenchyma with adipose tissue (fatty infiltration). This process results in the characteristic painless, "soft" swelling of the parotid glands. **Analysis of Options:** * **Aging (Option A):** While the parotid gland does undergo some physiological atrophy and minor fatty replacement with age, it rarely leads to the significant clinical "fatty change" or sialadenosis associated with systemic conditions like alcoholism. * **Malnutrition (Option C):** Malnutrition (specifically Kwashiorkor) is a known cause of sialadenosis; however, the primary histological feature in malnutrition is typically **acinar hypertrophy** (enlargement of cells) rather than predominant fatty infiltration. Alcoholism is the more specific and classic association for fatty replacement in this context. **Clinical Pearls for NEET-PG:** * **Sialadenosis "Rule of 3":** Remember the three main categories of causes: **Endocrine** (Diabetes Mellitus), **Nutritional** (Alcoholism, Vitamin deficiency, Bulimia), and **Drug-induced** (Guanethidine). * **Histology:** In alcoholic sialadenosis, look for **fatty infiltration** and **acinar cell hypertrophy** with preserved ductal architecture. * **Clinical Presentation:** Always look for "bilateral, painless, recurrent parotid swelling" in a patient with a history of liver disease or chronic alcohol intake.

Q: Which of the following occurs in Oral Submucous Fibrosis (OSMF)?

All of the above. **Explanation:** **Oral Submucous Fibrosis (OSMF)** is a chronic, insidious, premalignant condition characterized by progressive juxta-epithelial fibrosis of the oral cavity. It is primarily associated with the habit of chewing areca nut (betel nut). **Why "All of the above" is correct:** OSMF presents in stages, and the options represent the clinical spectrum of the disease: * **Stomatopyrosis (Option A):** This refers to a burning sensation in the mouth, which is often the earliest symptom. It is triggered by spicy foods due to the hypersensitivity of the thinning oral mucosa. * **Vesicles, Melanosis, and Xerostomia (Option B):** Early stages often involve the formation of small vesicles that rupture to form erosions. Chronic irritation leads to mucosal pigmentation (**melanosis**), and fibrosis of the minor salivary glands results in decreased salivation (**xerostomia**). * **Blanched Pallor and Stiffness (Option C):** As fibrosis progresses, the mucosa loses its vascularity and elasticity, appearing **marble-like or blanched**. Palpable vertical fibrous bands (especially in the buccal mucosa) lead to severe stiffness and restricted mouth opening (trismus). **Clinical Pearls for NEET-PG:** * **Etiology:** Areca nut (contains alkaloids like arecoline which stimulate collagen synthesis) and Copper (inhibits collagenase). * **Pathognomonic Sign:** Palpable vertical fibrous bands and "Hockey-stick" appearance of the uvula (due to fibrosis). * **Malignant Transformation:** OSMF is a **premalignant condition** with a transformation rate of approximately 7–13%, most commonly leading to Squamous Cell Carcinoma. * **Management:** Cessation of habit, intralesional steroids (to reduce inflammation), and Hyaluronidase (to break down ground substance). Surgical release is reserved for severe trismus.

Q: Which tumour is classically described as having a 'swiss cheese' appearance?

Adenoid cystic carcinoma. **Explanation:** **Adenoid Cystic Carcinoma (ACC)** is the correct answer. It is a slow-growing but aggressive malignant tumor of the salivary glands. The characteristic **"Swiss cheese" appearance** refers to its **Cribriform pattern**, where nests of tumor cells are punctuated by multiple small, round, cyst-like spaces (pseudo-lumina) containing basement membrane-like material or mucin. This histological feature is a classic "buzzword" for NEET-PG. **Analysis of Incorrect Options:** * **Rhabdomyosarcoma:** This is a malignant tumor of skeletal muscle origin. Histologically, it is characterized by "strap cells" or "tadpole cells" with cross-striations, not a cribriform pattern. * **Benign Mixed Tumour (Pleomorphic Adenoma):** This is the most common salivary gland tumor. It shows a mixture of epithelial and mesenchymal elements (chondroid or myxoid stroma), but lacks the classic Swiss cheese architecture. * **Meningioma:** These are tumors of the meninges. The classic histological hallmark is the presence of **Psammoma bodies** (laminated calcifications) and a whorled pattern of cells. **Clinical Pearls for NEET-PG:** * **Perineural Invasion:** ACC is notorious for spreading along nerves (perineural spread), often leading to pain or cranial nerve palsies (e.g., Facial nerve palsy). * **Most Common Site:** While it can occur in the parotid, it is the **most common malignant tumor of the minor salivary glands** and the submandibular gland. * **Prognosis:** It has a high recurrence rate and a tendency for late distant metastasis (most commonly to the **lungs**).

Q: A pipe smoker presents with a white, elevated plaque on their buccal mucosa, discovered during a general medical examination. This lesion cannot be wiped away with sterile gauze. What is the most likely diagnosis?

Leukoplakia. **Explanation:** The clinical presentation of a white, elevated plaque on the buccal mucosa that **cannot be wiped away** is the classic definition of **Leukoplakia**. According to the WHO, leukoplakia is a clinical term for a white patch or plaque that cannot be characterized clinically or pathologically as any other disease. In this case, the patient’s history of **pipe smoking** is a significant risk factor, as chronic irritation from tobacco and heat triggers hyperkeratosis of the epithelium. **Analysis of Options:** * **Thrush (Oral Candidiasis):** While it presents as white patches, these are "pseudomembranous" and **can be easily scraped off** with gauze, leaving an erythematous (red), bleeding base. * **Squamous Cell Carcinoma (SCC):** While leukoplakia is a premalignant condition that can progress to SCC, a localized, asymptomatic white plaque without ulceration, induration, or rapid growth is more characteristic of the precursor lesion (leukoplakia) rather than frank malignancy. * **Gingivitis:** This refers specifically to inflammation of the gums (gingiva), characterized by redness, swelling, and bleeding, rather than a white plaque on the buccal mucosa. **High-Yield Clinical Pearls for NEET-PG:** * **Biopsy is mandatory:** Since 3–6% of leukoplakic patches undergo malignant transformation, a biopsy is required to rule out dysplasia or carcinoma. * **Erythroplakia:** A red, velvety patch in the mouth has a much higher risk of malignancy than leukoplakia. * **Speckled Leukoplakia:** A mix of white and red areas; it carries the highest risk of malignant transformation among leukoplakic lesions. * **Hairy Leukoplakia:** Associated with EBV in HIV-positive patients; typically occurs on the lateral borders of the tongue and is *not* premalignant.

Q: Sialoliths are most common in which of the following ducts?

Wharton duct. **Explanation:** Sialolithiasis (salivary calculi) occurs most frequently in the **Wharton duct**, which drains the submandibular gland. Approximately **80-90%** of all salivary stones are found here. **Why the Wharton Duct is the most common site:** 1. **Anatomical Course:** The duct follows a long, upward, and tortuous path, leading to salivary stasis. 2. **Saliva Composition:** Submandibular saliva is more alkaline and has a higher concentration of calcium and phosphate compared to parotid saliva. 3. **Viscosity:** The gland produces a mixture of serous and mucous secretions, making the saliva more viscous. 4. **Punctum Size:** The orifice (opening) of the Wharton duct is smaller than the duct's lumen, facilitating the entrapment of stones. **Analysis of Incorrect Options:** * **A. Stenson duct:** Drains the parotid gland. Only about 10-15% of stones occur here because parotid saliva is purely serous (thin) and the duct is shorter and wider. * **C. Bartholin duct:** This is the major duct of the sublingual gland. Stones here are rare (approx. 1-5%). * **D. Duct of Rivinus:** These are the multiple minor ducts of the sublingual gland. Due to their small size and constant flow, stone formation is clinically uncommon. **High-Yield Clinical Pearls for NEET-PG:** * **Radiopacity:** 80% of submandibular stones are **radiopaque** (visible on X-ray), whereas 80% of parotid stones are **radiolucent**. * **Clinical Presentation:** Post-prandial pain and swelling (mealtime syndrome) are classic symptoms. * **Investigation of Choice:** Non-contrast CT (NCCT) is highly sensitive; however, **Sialography** is the gold standard for ductal anatomy (though contraindicated in acute infection). * **Management:** Small stones may be massaged out; larger stones require **Sialendoscopy** or surgical excision.

Q: Mixed tumours of the salivary glands are:

Most common in the parotid gland. **Explanation:** **Mixed Tumors (Pleomorphic Adenoma)** are the most common benign neoplasms of the salivary glands. They are termed "mixed" because they contain both epithelial and mesenchymal elements (myxoid, chondroid, or osteoid tissue). 1. **Why Option C is Correct:** The parotid gland is the most frequent site for salivary gland tumors. Approximately 80% of all salivary gland tumors occur in the parotid, and about 80% of these are Pleomorphic Adenomas. Therefore, the parotid gland is the most common site for mixed tumors. 2. **Why Option A is Incorrect:** While mixed tumors can occur in the submandibular gland, they are significantly less common there than in the parotid. Only about 10% of salivary tumors occur in the submandibular gland. 3. **Why Option B is Incorrect:** Pleomorphic adenomas are **benign**. Although they have a risk of malignant transformation (becoming *Carcinoma ex pleomorphic adenoma*), this occurs in only about 3–5% of cases, usually after the tumor has been present for many years. 4. **Why Option D is Incorrect:** Salivary calculi (Sialolithiasis) are most commonly associated with the **submandibular gland** (80% of cases) due to the alkaline nature and high calcium content of its secretions, not with mixed tumors. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site:** Superficial lobe of the parotid gland. * **Clinical presentation:** A painless, slow-growing, mobile, firm "swelling below and in front of the ear." * **Treatment of choice:** Superficial parotidectomy (to avoid recurrence and preserve the facial nerve). Enucleation is contraindicated due to the presence of a "pseudocapsule" and finger-like projections. * **Rule of 80:** 80% occur in the parotid; 80% are benign; 80% are Pleomorphic Adenoma.

Question 1

What is the most common malignant tumor of the salivary glands?

Accepted Answer

Mucoepidermoid carcinoma

Answer

Pleomorphic adenoma

Answer

Warthin tumor

Answer

Adenoid cystic carcinoma

Question 2

Parotid fatty change is a sign of?

Accepted Answer

Alcoholism

Answer

Aging

Answer

Malnutrition

Answer

None of the above

Question 3

Which of the following occurs in Oral Submucous Fibrosis (OSMF)?

Accepted Answer

All of the above

Answer

Stomatopyrosis

Answer

Vesicles, melanosis, and xerostomia

Answer

Blanched pallor with hard subepithelial stiffness

Question 4

Which tumour is classically described as having a 'swiss cheese' appearance?

Accepted Answer

Adenoid cystic carcinoma

Answer

Rhabdomyosarcoma

Answer

Benign mixed tumour

Answer

Meningioma

Question 5

A pipe smoker presents with a white, elevated plaque on their buccal mucosa, discovered during a general medical examination. This lesion cannot be wiped away with sterile gauze. What is the most likely diagnosis?

Accepted Answer

Leukoplakia

Answer

Squamous cell carcinoma

Answer

Thrush

Answer

Gingivitis

Question 6

Which salivary gland tumor is associated with smoking?

Accepted Answer

Warthin tumour

Answer

Cannicular adenoma

Answer

Pleomorphic adenoma

Answer

Ductal papilloma

Question 7

Sialoliths are most common in which of the following ducts?

Accepted Answer

Wharton duct

Answer

Stenson duct

Answer

Bartholin duct

Answer

Duct of Rivinus

Question 8

Adamantinoma is what type of tumor?

Accepted Answer

None of the above

Answer

A tumor derived from the enamel organ or cells that produce enamel

Answer

Also known as ameloblastoma

Answer

A tumor that arises from the basal cell layer of the epidermis

Question 9

Mixed tumours of the salivary glands are:

Accepted Answer

Most common in the parotid gland

Answer

Most common in the submandibular gland

Answer

Usually malignant

Answer

Associated with calculi

Question 10

Dilation of the salivary duct secondary to epithelial atrophy as a result of repeated inflammatory or infectious process is termed as?

Accepted Answer

Sialodochitis

Answer

Sialadenitis

Answer

Sialolithiasis

Answer

Mucocele

Diseases of the Oral Cavity and Salivary Glands — MCQs

Diseases of the Oral Cavity and Salivary Glands — MCQs

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