Diseases of the Oral Cavity and Salivary Glands — MCQs

Diseases of the Oral Cavity and Salivary Glands Indian Medical PG Practice Questions and MCQs

Question 261: What is the most common malignant tumor of the salivary glands?

A. Pleomorphic adenoma
B. Warthin tumor
C. Adenoid cystic carcinoma
D. Mucoepidermoid carcinoma (Correct Answer)

Explanation: **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).

Question 262: Parotid fatty change is a sign of?

A. Aging
B. Alcoholism (Correct Answer)
C. Malnutrition
D. None of the above

Explanation: **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.

Question 263: Which of the following occurs in Oral Submucous Fibrosis (OSMF)?

A. Stomatopyrosis
B. Vesicles, melanosis, and xerostomia
C. Blanched pallor with hard subepithelial stiffness
D. All of the above (Correct Answer)

Explanation: **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.

Question 264: Which tumour is classically described as having a 'swiss cheese' appearance?

A. Rhabdomyosarcoma
B. Benign mixed tumour
C. Adenoid cystic carcinoma (Correct Answer)
D. Meningioma

Explanation: **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**).

Question 265: 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?

A. Squamous cell carcinoma
B. Thrush
C. Gingivitis
D. Leukoplakia (Correct Answer)

Explanation: **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.

Question 266: Which salivary gland tumor is associated with smoking?

A. Cannicular adenoma
B. Pleomorphic adenoma
C. Warthin tumour (Correct Answer)
D. Ductal papilloma

Explanation: ### Explanation **Correct Answer: C. Warthin tumour** **Medical Concept:** Warthin tumour (also known as **Papillary Cystadenoma Lymphomatosum**) is a benign salivary gland tumor with a unique and strong association with **cigarette smoking**. Smokers have an approximately **8-fold increased risk** of developing this tumor compared to non-smokers. It is hypothesized that irritants in tobacco smoke may trigger metaplasia or inflammation in the parotid ductal epithelium trapped within intra-parotid lymph nodes. **Analysis of Options:** * **A. Canalicular adenoma:** This is a minor salivary gland tumor, most commonly found in the upper lip. It has no established link to smoking. * **B. Pleomorphic adenoma:** This is the most common salivary gland tumor overall. While it is the most frequent benign tumor of the parotid, its etiology is not specifically linked to smoking. * **D. Ductal papilloma:** These are rare benign tumors arising from the salivary gland ducts (e.g., inverted ductal papilloma). They do not share the strong epidemiological link to smoking seen in Warthin tumour. **High-Yield Clinical Pearls for NEET-PG:** * **Location:** Almost exclusively occurs in the **Parotid gland** (specifically the tail/lower pole). It is the most common salivary tumor to present **bilaterally** (10%) or multicentrically. * **Demographics:** Classically seen in **older males** (though the male-to-female ratio is narrowing as smoking habits change). * **Diagnosis:** On **99mTc-Pertechnetate scan**, Warthin tumour appears as a **"Hot Nodule"** because the oncocytes concentrate the isotope but cannot secrete it. * **Pathology:** Characterized by a double layer of oncocytic epithelium forming papillary projections into cystic spaces, surrounded by a dense lymphoid stroma with germinal centers. * **Treatment:** Surgical excision (Superficial parotidectomy or Enucleation). It has a very low recurrence rate and almost zero malignant transformation potential.

Question 267: Sialoliths are most common in which of the following ducts?

A. Stenson duct
B. Wharton duct (Correct Answer)
C. Bartholin duct
D. Duct of Rivinus

Explanation: **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.

Question 268: Adamantinoma is what type of tumor?

A. A tumor derived from the enamel organ or cells that produce enamel
B. Also known as ameloblastoma
C. A tumor that arises from the basal cell layer of the epidermis
D. None of the above (Correct Answer)

Explanation: **Explanation:** The correct answer is **None of the above** because the term **Adamantinoma** refers to a rare, low-grade malignant primary bone tumor, most commonly found in the **tibia**. While historically the term was used interchangeably with ameloblastoma, modern pathology distinguishes them as two distinct entities. **1. Why Option D is correct:** In contemporary medical nomenclature, Adamantinoma is a **mesenchymal bone tumor** characterized by nests of epithelial cells surrounded by a spindle-cell stroma. It typically affects the pretibial cortex of young adults. It is *not* an odontogenic tumor, nor is it a basal cell carcinoma. **2. Why the other options are incorrect:** * **Option A:** This describes an **Ameloblastoma**. While "Adamantinoma of the jaw" was an old name for ameloblastoma, it is now considered an obsolete and technically incorrect synonym. Ameloblastomas arise from odontogenic epithelium but do *not* produce enamel (as the cells do not reach the functional stage of ameloblasts). * **Option B:** As stated above, while historically linked, they are now recognized as different pathologies. Ameloblastoma is an odontogenic tumor of the jaw, whereas Adamantinoma is a primary bone tumor of the long bones. * **Option C:** This describes a **Basal Cell Carcinoma (BCC)**. While some histological variants of BCC can mimic the pattern of an ameloblastoma (fibroepithelioma of Pinkus), they are etiologically unrelated. **Clinical Pearls for NEET-PG:** * **Location:** 80-90% of Adamantinomas occur in the **Tibia**. * **Radiology:** Appears as multiple, well-circumscribed radiolucent lesions with a "soap-bubble" appearance in the mid-shaft of the tibia. * **Differential Diagnosis:** Must be distinguished from **Osteofibrous Dysplasia (OFD)**; some experts believe Adamantinoma and OFD exist on a clinicopathological spectrum. * **Ameloblastoma Key Fact:** Most common site is the **mandible (molar-ramus area)**; it is "benign but locally invasive."

Question 269: Mixed tumours of the salivary glands are:

A. Most common in the submandibular gland
B. Usually malignant
C. Most common in the parotid gland (Correct Answer)
D. Associated with calculi

Explanation: **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 270: Dilation of the salivary duct secondary to epithelial atrophy as a result of repeated inflammatory or infectious process is termed as?

A. Sialodochitis (Correct Answer)
B. Sialadenitis
C. Sialolithiasis
D. Mucocele

Explanation: ### Explanation **Correct Answer: A. Sialodochitis** **Understanding the Concept:** Sialodochitis refers specifically to the **inflammation of the salivary duct system**. When the salivary ducts undergo repeated episodes of infection or inflammation, the ductal epithelium undergoes atrophy and loses its elasticity. This structural weakening leads to irregular dilation and narrowing of the duct (often described as a "sausage-string" appearance on sialography). The key distinction here is the anatomical site: *Sialodochitis* involves the **duct**, whereas *Sialadenitis* involves the **gland parenchyma**. **Analysis of Incorrect Options:** * **B. Sialadenitis:** This is a general term for inflammation of the **salivary gland parenchyma** (the secretory tissue) rather than the ductal system. While it often co-exists with sialodochitis, it does not specifically describe the dilation of the duct due to epithelial atrophy. * **C. Sialolithiasis:** This refers to the formation of **calculi (stones)** within the salivary gland or its ducts. While stones can cause secondary dilation (obstructive sialodochitis), the term itself refers to the stone, not the pathological dilation of the duct wall. * **D. Mucocele:** This is a clinical term for a mucus-filled cyst caused by the **rupture** of a minor salivary gland duct (extravasation) or, less commonly, a blocked duct (retention). It typically presents as a bluish, translucent swelling on the lower lip. **High-Yield Clinical Pearls for NEET-PG:** * **Sialography Finding:** Chronic sialodochitis typically shows a **"Sausage-string appearance"** (segments of dilation and stenosis). * **Küttner’s Tumor:** A chronic sclerosing sialadenitis of the submandibular gland that mimics a neoplasm. * **Most common site for Sialolithiasis:** Submandibular gland (Wharton’s duct) due to the alkaline, calcium-rich nature of the saliva and the upward, tortuous course of the duct. * **Mumps:** The most common viral cause of acute sialadenitis, typically affecting the parotid gland.

Practice by Chapter

Stomatitis

Practice Questions

Oral Ulcers

Practice Questions

Oral Leukoplakia

Practice Questions

Oral Cancers

Practice Questions

Sialadenitis

Practice Questions

Sialolithiasis

Practice Questions

Salivary Gland Tumors

Practice Questions

Ranula

Practice Questions

Xerostomia

Practice Questions

Sjögren's Syndrome

Practice Questions

Oral Manifestations of Systemic Diseases

Practice Questions

Temporomandibular Joint Disorders

Practice Questions

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