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 251: All of the following are true about mucoepidermoid carcinoma except?

A. Most common radiation-induced neoplasm of the parotid gland.
B. Most common malignant salivary gland tumor in children.
C. Usually causes facial paralysis. (Correct Answer)
D. Poorly differentiated in adults.

Explanation: **Explanation:** Mucoepidermoid carcinoma (MEC) is the most common malignant tumor of the salivary glands. The correct answer is **C** because facial nerve paralysis is **uncommon** in MEC, occurring in only about 10–15% of cases. Facial nerve involvement is typically a feature of high-grade malignancies or advanced stages; most MECs are low-grade and present as slow-growing, painless masses. **Analysis of Options:** * **Option A:** MEC is indeed the most common **radiation-induced** salivary gland neoplasm, often appearing years after exposure to ionizing radiation. * **Option B:** It is the most common **malignant** salivary gland tumor in both children and adults. (Note: Pleomorphic adenoma is the most common *benign* tumor in children). * **Option D:** While MEC can be low, intermediate, or high-grade, it tends to be **more aggressive and poorly differentiated in adults** compared to the pediatric population, where low-grade variants predominate. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site:** Parotid gland (overall), but it is also the most common malignancy of the minor salivary glands (especially the palate). * **Histology:** Characterized by a mixture of three cell types: **Mucin-producing cells**, **Epidermoid (squamous) cells**, and **Intermediate cells**. * **Staining:** Mucicarmine stain is used to identify the intracellular mucin. * **Grading:** The prognosis depends heavily on the histological grade rather than just the TNM stage. Low-grade tumors have a 5-year survival rate of >90%.

Question 252: Perforation of the palate is seen with which of the following conditions?

A. Minor aphthous ulcers
B. Major aphthous ulcers
C. Tertiary syphilis (Correct Answer)
D. All of the above

Explanation: **Explanation:** **Tertiary Syphilis (Correct Answer):** The hallmark lesion of tertiary syphilis is the **Gumma**, a chronic granulomatous lesion characterized by endarteritis obliterans. When a gumma involves the hard palate, it leads to localized ischemia and necrosis of the underlying bone, eventually causing a midline, painless **perforation of the palate**. This creates an oronasal communication, leading to nasal regurgitation of food and hypernasal speech. **Incorrect Options:** * **Minor Aphthous Ulcers:** These are small (<10mm), shallow, painful ulcers that involve only the non-keratinized mucosa. They heal within 7–10 days without scarring and never involve the underlying bone or cause perforation. * **Major Aphthous Ulcers (Sutton’s Disease):** While these are larger (>10mm), deeper, and more painful than minor ulcers, they typically involve the soft tissues (lips, soft palate, fauces). Although they may heal with scarring, they do not cause full-thickness bony perforation of the hard palate. **High-Yield Clinical Pearls for NEET-PG:** * **Midline Perforation:** Always think of **Tertiary Syphilis** or **Wegener’s Granulomatosis** (Granulomatosis with Polyangiitis). * **Lateral Perforation:** More commonly associated with **Malignancy** (e.g., Squamous cell carcinoma of the maxillary sinus or palate) or **Mucormycosis** in immunocompromised patients. * **Cocaine Abuse:** Chronic intranasal cocaine use is a common non-infectious cause of midline palatal perforation due to intense vasoconstriction. * **Congenital Syphilis Triad (Hutchinson’s):** Hutchinson’s teeth, Interstitial keratitis, and Eighth nerve deafness.

Question 253: Intraoral pleomorphic adenoma most commonly occurs in which location?

A. Buccal mucosa
B. Upper lip
C. Floor of the mouth
D. Palate (Correct Answer)

Explanation: **Explanation:** **Pleomorphic Adenoma (Benign Mixed Tumor)** is the most common salivary gland tumor overall. While it most frequently involves the parotid gland (extraoral), it can also arise from the minor salivary glands distributed throughout the oral cavity. 1. **Why Palate is Correct:** The **hard palate** is the most common site for minor salivary gland tumors, including pleomorphic adenoma. This is due to the high density of minor salivary glands located in the posterolateral aspect of the hard palate. Clinically, it presents as a slow-growing, painless, firm, and non-ulcerated swelling that does not move against the underlying bone (due to the tight mucoperiosteum). 2. **Why Other Options are Incorrect:** * **Upper Lip:** This is the second most common site for minor salivary gland pleomorphic adenomas. Interestingly, benign tumors are more common in the upper lip, whereas malignant minor salivary tumors are more common in the lower lip. * **Buccal Mucosa:** While minor salivary glands exist here, tumors in this location are significantly less frequent than those on the palate. * **Floor of the Mouth:** This is a rare site for pleomorphic adenoma. Swellings here are more likely to be ranulas, dermoid cysts, or tumors of the sublingual gland (which are frequently malignant). **High-Yield Clinical Pearls for NEET-PG:** * **Most common site (Overall):** Parotid gland (Superficial lobe). * **Most common site (Minor Salivary Glands):** Palate. * **Clinical Feature:** It is called "mixed tumor" because it contains both epithelial and mesenchymal (mucoid, chondroid) elements. * **Treatment:** Wide local excision with a cuff of normal tissue. Simple enucleation is avoided due to the presence of **pseudopods** (microscopic projections), which lead to high recurrence rates.

Question 254: What is the most common tumor of minor salivary glands?

A. Mucoepidermoid carcinoma (Correct Answer)
B. Mixed tumor
C. Squamous cell carcinoma
D. Epithelioma

Explanation: **Explanation:** The distribution and frequency of salivary gland tumors follow specific patterns based on the site of origin. While the Parotid gland is the most common site for salivary tumors overall, the **minor salivary glands** (found throughout the oral cavity, palate, and lips) have a higher propensity for malignancy. **1. Why Mucoepidermoid Carcinoma is correct:** **Mucoepidermoid carcinoma (MEC)** is the most common malignant tumor of the salivary glands overall and specifically the **most common tumor (and most common malignancy) of the minor salivary glands.** It typically presents as a painless, firm swelling, most frequently located on the hard palate. **2. Why the other options are incorrect:** * **Mixed Tumor (Pleomorphic Adenoma):** This is the most common tumor of the **major** salivary glands (especially the Parotid). While it can occur in minor glands, MEC surpasses it in frequency in these locations. * **Squamous Cell Carcinoma:** While this is the most common cancer of the oral cavity lining (mucosa), it does not arise from the glandular tissue itself. * **Epithelioma:** This is a non-specific term for epithelial tumors and is not a recognized primary classification for salivary gland neoplasms in this context. **High-Yield Clinical Pearls for NEET-PG:** * **The Rule of 80s (Parotid):** 80% of tumors are in the Parotid; 80% of Parotid tumors are Pleomorphic Adenomas; 80% are benign. * **Minor Salivary Glands:** Unlike the Parotid, nearly **50-60%** of minor salivary gland tumors are **malignant**. * **Adenoid Cystic Carcinoma:** This is the second most common malignancy of minor salivary glands and is notorious for **perineural invasion** and "skip lesions." * **Most common site for Minor Salivary Gland tumors:** The Palate.

Question 255: What is meant by Carcinoma Ex pleomorphic adenoma?

A. Malignant change of pleomorphic adenoma (Correct Answer)
B. Regrowth of pleomorphic adenoma after superficial parotidectomy due to inadequate removal
C. Painless condition
D. Slow and progressive growth of pleomorphic adenoma

Explanation: **Explanation:** **Carcinoma ex pleomorphic adenoma (CXPA)** is defined as a carcinoma arising from a pre-existing benign pleomorphic adenoma (mixed tumor). It represents a malignant transformation where the epithelial component of the benign tumor undergoes cancerous changes. * **Why Option A is Correct:** The term "Ex" signifies "out of" or "from." Clinically, this is suspected when a long-standing, slow-growing parotid mass suddenly undergoes rapid enlargement, becomes painful, or causes facial nerve palsy. Histologically, one finds areas of classic benign pleomorphic adenoma alongside areas of frank malignancy (usually adenocarcinoma or undifferentiated carcinoma). * **Why Other Options are Incorrect:** * **Option B:** Regrowth after inadequate removal is termed **Recurrent Pleomorphic Adenoma**. This is usually due to "seeding" or rupture of the capsule during surgery, but the tumor remains histologically benign. * **Option C:** Unlike benign pleomorphic adenomas, CXPA is often associated with **pain**, skin fixation, and lymphadenopathy. * **Option D:** Slow and progressive growth is a hallmark of the **benign** version. A sudden change in growth rate is the red flag for malignancy. **High-Yield NEET-PG Pearls:** 1. **Risk Factor:** The risk of malignant transformation increases with the duration of the tumor (approx. 1.5% in the first 5 years, rising to nearly 10% after 15 years). 2. **Most Common Site:** The Parotid gland. 3. **Clinical Sign:** New-onset **Facial Nerve Palsy** in a patient with a chronic parotid lump is the most pathognomonic sign of malignancy. 4. **Treatment:** Radical parotidectomy often followed by radiotherapy.

Question 256: Which statement is true regarding tumors of the sublingual gland?

A. Most tumors are benign.
B. Painless swelling is a common presentation. (Correct Answer)
C. Neck dissection is never performed.
D. All of the above

Explanation: ### Explanation **1. Why the Correct Answer is Right:** The sublingual gland is the smallest of the major salivary glands. Like most salivary gland neoplasms, the most frequent clinical presentation is a **slow-growing, painless swelling** in the floor of the mouth. Because these tumors are often asymptomatic in the early stages, patients may delay seeking medical attention until the mass interferes with tongue mobility or speech. **2. Why the Incorrect Options are Wrong:** * **Option A (Most tumors are benign):** This is incorrect. There is an inverse relationship between the size of the salivary gland and the risk of malignancy (**Rule of 80s/20s**). While 80% of parotid tumors are benign, approximately **70–90% of sublingual gland tumors are malignant** (most commonly Adenoid Cystic Carcinoma). * **Option B (Neck dissection is never performed):** This is incorrect. Since sublingual tumors have a high rate of malignancy, surgical management often involves wide local excision (including the overlying mucosa and sometimes a portion of the mandible). If there is clinical evidence of nodal metastasis or if the pathology is high-grade (e.g., Mucoepidermoid carcinoma), a **neck dissection** is indicated. **3. High-Yield Clinical Pearls for NEET-PG:** * **Malignancy Risk:** Sublingual gland (80-90%) > Submandibular gland (40-50%) > Parotid gland (20-25%). * **Most Common Malignancy:** **Adenoid Cystic Carcinoma** is the most common malignant tumor of the sublingual gland (noted for its propensity for perineural invasion). * **Anatomy:** The sublingual gland lies above the mylohyoid muscle; a swelling here must be differentiated from a **Ranula** (plunging ranulas extend below the mylohyoid). * **The "Rule of 80s" for Parotid:** 80% are in the superficial lobe, 80% are Pleomorphic Adenoma, and 80% are benign.

Question 257: Which tumor is exclusively seen in the parotid gland?

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

Explanation: **Explanation:** The correct answer is **Warthin tumor** (also known as Papillary Cystadenoma Lymphomatosum). **Why Warthin Tumor is the correct answer:** Warthin tumor is unique because it arises from **salivary gland tissue entrapped within intra-parotid lymph nodes** during embryogenesis. Since lymph nodes are incorporated into the parotid gland capsule during development (a feature not seen in the submandibular or sublingual glands), Warthin tumor is found **exclusively in the parotid gland** (specifically the tail of the parotid). **Analysis of Incorrect Options:** * **A. Mucoepidermoid carcinoma:** This is the most common malignant salivary gland tumor. While it frequently occurs in the parotid, it is also the most common malignancy of the minor salivary glands and can occur in the submandibular gland. * **B. Adenoid cystic carcinoma:** This is the most common malignant tumor of the **minor salivary glands** and the submandibular gland. It is notorious for perineural invasion. * **C. Pleomorphic adenoma:** This is the most common benign tumor of all salivary glands. While 80% occur in the parotid, it frequently involves the submandibular and minor salivary glands (especially the palate). **High-Yield Clinical Pearls for NEET-PG:** * **Hot Spot:** Warthin tumor is the only salivary gland tumor that shows increased uptake on a **Technetium-99m pertechnetate scan** (Hot tumor). * **Risk Factor:** It has a very strong association with **smoking**. * **Demographics:** Classically seen in elderly males (though the male-to-female ratio is narrowing). * **Bilateralism:** It is the most common salivary gland tumor to present **bilaterally** or multicentrically (10% of cases). * **Malignancy:** It has the lowest potential for malignant transformation among salivary tumors.

Question 258: Ludwig's angina usually begins in which space?

A. Submandibular space (Correct Answer)
B. Sublingual space
C. Parotid space
D. Retropharyngeal space

Explanation: **Explanation:** **Ludwig’s Angina** is a rapidly spreading, life-threatening cellulitis involving the submandibular, sublingual, and submental spaces bilaterally. **Why Submandibular Space is Correct:** The infection most commonly originates from the **lower second and third molar teeth** (80% of cases). The roots of these teeth extend below the level of the **mylohyoid muscle** attachment on the mandible. Consequently, an apical abscess at these sites drains directly into the **submandibular space**. From here, the infection spreads contiguously via the posterior border of the mylohyoid muscle to involve the sublingual and submental spaces. **Why Other Options are Incorrect:** * **Sublingual space:** While this space is involved in Ludwig’s Angina (causing the characteristic elevation of the tongue), it is usually involved secondary to the submandibular space. Infections starting here typically arise from the premolars or the first molar. * **Parotid space:** This space contains the parotid gland and facial nerve. Infections here (parotitis) present with pre-auricular swelling, not the "woody" neck edema seen in Ludwig’s Angina. * **Retropharyngeal space:** Infections here are common in children (lymph node suppuration) and can lead to airway obstruction, but they do not manifest as the bilateral floor-of-mouth cellulitis characteristic of Ludwig’s Angina. **Clinical Pearls for NEET-PG:** * **Clinical Feature:** "Woody" or "Brawny" edema of the neck with superior-posterior displacement of the tongue. * **Primary Risk:** Asphyxia due to laryngeal edema/tongue displacement (Airway management is the priority). * **Microbiology:** Usually polymicrobial (Streptococci, Staphylococci, and anaerobes). * **Management:** High-dose IV antibiotics, airway protection, and incision and drainage (I&D) if there is fluctuance or failed medical management.

Question 259: Recurrent aphthae resemble recurrent herpes in that:

A. Symptoms are similar (Correct Answer)
B. Lifelong immunity results
C. Vesicles occur with both diseases
D. Intranuclear inclusion bodies are present

Explanation: ### Explanation **Correct Option: A. Symptoms are similar** Recurrent Aphthous Stomatitis (RAS) and Recurrent Herpes Simplex (Herpes Labialis/Stomatitis) share a very similar clinical presentation. Both conditions are characterized by **recurrent, painful, ulcerative lesions** in the oral cavity that are often preceded by a **prodromal sensation** of burning or tingling. Because both cause significant discomfort and follow a periodic pattern of eruption and healing, they are frequently confused in clinical practice. **Analysis of Incorrect Options:** * **B. Lifelong immunity results:** Neither condition confers immunity. RAS is a chronic inflammatory condition with a multifactorial etiology (stress, trauma, genetics), and Herpes is caused by a latent virus (HSV-1) that reactivates periodically. * **C. Vesicles occur with both diseases:** This is a key differentiating factor. **Herpes is a primary vesicular disease** (vesicles form and then rupture into ulcers). **Aphthous ulcers never form vesicles**; they begin directly as erythematous macules that quickly ulcerate. * **D. Intranuclear inclusion bodies are present:** These (specifically Cowdry Type A bodies) are characteristic of viral infections like Herpes. They are **absent in Aphthous ulcers**, which show non-specific inflammatory changes on histology. **High-Yield Clinical Pearls for NEET-PG:** * **Location Tip:** Aphthous ulcers occur almost exclusively on **non-keratinized/mobile mucosa** (buccal mucosa, floor of mouth). Recurrent Herpes typically affects **keratinized/fixed mucosa** (hard palate, gingiva) or the vermilion border of the lips. * **Herpetiform Aphthous Ulcers:** A subtype of RAS that presents as multiple tiny crops of ulcers. Despite the name, they are **not** caused by the Herpes virus. * **Behcet’s Syndrome:** Always consider this if oral aphthae are associated with genital ulcers and uveitis.

Question 260: Which structures become enlarged in the condition known as "Hairy Tongue"?

A. Fungiform papillae
B. Filiform papillae (Correct Answer)
C. Circumvallate papillae
D. Taste buds

Explanation: **Explanation:** **Hairy Tongue (Lingua Villosa)** is a benign clinical condition characterized by the marked hypertrophy and elongation of the **filiform papillae** on the dorsal surface of the tongue. 1. **Why Filiform Papillae is correct:** Under normal conditions, filiform papillae undergo constant desquamation. In Hairy Tongue, there is a lack of normal shedding (hyperkeratosis), causing these papillae to grow up to 15–18 mm in length. This creates a "hair-like" appearance. These elongated papillae trap debris, bacteria, and fungi (like *Candida albicans*), leading to secondary discoloration—most commonly black (**Black Hairy Tongue**) or brown. 2. **Why other options are incorrect:** * **Fungiform papillae:** These are mushroom-shaped structures scattered among filiform papillae, primarily involved in taste. They do not undergo the keratinization process required to produce a "hairy" appearance. * **Circumvallate papillae:** These are large, V-shaped papillae at the back of the tongue. While they contain taste buds and Von Ebner’s glands, they do not elongate in this condition. * **Taste buds:** These are microscopic sensory organs located within the papillae. Hairy tongue is a structural defect of the keratinized surface, not a proliferation of sensory cells. **High-Yield Clinical Pearls for NEET-PG:** * **Etiology:** Associated with poor oral hygiene, heavy smoking, excessive coffee/tea intake, and use of broad-spectrum antibiotics (which alter oral flora). * **Site:** Usually involves the **posterior two-thirds** of the tongue dorsum, anterior to the circumvallate papillae. * **Management:** Primarily involves tongue scraping/brushing and cessation of predisposing factors (e.g., smoking). * **Differential Diagnosis:** Do not confuse with **Oral Hairy Leukoplakia** (caused by EBV in HIV patients), which typically occurs on the *lateral* borders of the tongue and does not scrape off.

Practice by Chapter

Stomatitis

Practice Questions

Oral Ulcers

Practice Questions

Oral Leukoplakia

Practice Questions

Oral Cancers

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Sialadenitis

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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

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