Diseases of the Oral Cavity and Salivary Glands — MCQs

A 40-year-old female presented with bilateral parotid gland enlargement, dry eyes, dry mouth, chronic non-productive cough, and shortness of breath. On examination, hepatosplenomegaly was noted. CT scan of the chest and salivary gland biopsy were performed. Which of the following interleukins is involved in the pathogenesis of this disease?

Q78Easy

What is the most likely consequence of a sialolith (salivary stone) in the excretory duct?

Q79Medium

All of the following are true about Ranula except:

Q80Medium

A 70-year-old male presented with an asymptomatic white patch on the oral cavity following the application of a denture. What is the treatment of choice?

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

Question 71: How can tuberculosis be easily differentiated from squamous cell carcinoma?

A. Acid-fast bacilli positive with Ziehl-Neelsen stain
B. Primary lesion occurs on the tongue
C. Biopsy can confirm the diagnosis (Correct Answer)
D. Direct smear examination

Explanation: **Explanation:** The differentiation between **Tuberculosis (TB)** and **Squamous Cell Carcinoma (SCC)** of the oral cavity is a classic clinical challenge because both can present as a chronic, non-healing, painful ulcer with indurated margins. 1. **Why Biopsy is the Correct Answer:** Histopathology is the **gold standard** for definitive diagnosis. A biopsy provides a tissue-level view that distinguishes between the **caseating granulomas** (epithelioid cells and Langhans giant cells) characteristic of TB and the **malignant epithelial cells** (with keratin pearls and nuclear atypia) characteristic of SCC. While other tests suggest the etiology, only a biopsy can confirm or rule out malignancy with certainty. 2. **Analysis of Incorrect Options:** * **Option A & D:** While ZN staining for Acid-Fast Bacilli (AFB) or direct smears can support a TB diagnosis, they have **low sensitivity** in oral lesions. A negative smear does not rule out TB, nor does it rule out a co-existing malignancy. * **Option B:** Both TB and SCC frequently involve the tongue (the most common site for oral TB). Therefore, the anatomical location is not a differentiating factor. **High-Yield Clinical Pearls for NEET-PG:** * **Oral TB Presentation:** Usually secondary to pulmonary TB; presents as a painful, irregular ulcer with undermined edges and a pale base. * **SCC Presentation:** Presents as a painless or painful ulcer with **everted (rolled-out) edges** and an indurated base. * **Rule of Thumb:** Any oral ulcer persisting for more than **3 weeks** must undergo a biopsy to exclude Squamous Cell Carcinoma.

Question 72: Bilateral parotid enlargement occurs in all of the following conditions except?

A. Sjogren's syndrome
B. Systemic lupus erythematosus (SLE) (Correct Answer)
C. Sarcoidosis
D. Chronic pancreatitis

Explanation: **Explanation:** The question asks for the condition that does **not** typically present with bilateral parotid enlargement. **1. Why SLE is the Correct Answer:** While Systemic Lupus Erythematosus (SLE) is an autoimmune disease that can affect multiple organ systems, it is **not** a classic cause of bilateral parotid swelling. In SLE, salivary gland involvement is rare unless it occurs as "Secondary Sjogren’s Syndrome." On its own, SLE typically presents with malar rashes, joint pain, and renal issues rather than primary parotid hypertrophy. **2. Analysis of Incorrect Options:** * **Sjogren’s Syndrome:** This is a classic cause of bilateral, painless parotid enlargement (seen in ~50% of patients) due to lymphocytic infiltration of the exocrine glands. * **Sarcoidosis:** Can cause bilateral parotid enlargement, famously known as **Heerfordt’s Syndrome** (Uveoparotid fever), which consists of parotid swelling, uveitis, and facial nerve palsy. * **Chronic Pancreatitis:** This is associated with **Sialadenosis** (non-inflammatory, non-neoplastic swelling). Sialadenosis is frequently seen in systemic metabolic conditions, including chronic alcoholism, malnutrition, and chronic pancreatitis, due to autonomic neuropathy affecting the acinar cells. **3. NEET-PG High-Yield Pearls:** * **Sialadenosis (Bilateral Swelling):** Remember the "3 Ms": **M**etabolic (Diabetes), **M**alnutrition (Alcoholism/Bulimia), and **M**edications (Guanethidine). * **Warthin’s Tumor:** The most common **neoplastic** cause of bilateral parotid tumors (though usually metachronous). * **Mumps:** The most common **viral** cause of acute bilateral parotid swelling in children. * **Heerfordt’s Syndrome:** A high-yield triad in Sarcoidosis: Parotitis + Uveitis + Facial Palsy.

Question 73: What is the most common site for minor salivary gland tumors?

A. Cheek
B. Palate (Correct Answer)
C. Sublingual gland
D. Tongue

Explanation: **Explanation:** The **palate** (specifically the hard palate) is the most common site for minor salivary gland tumors, accounting for approximately **40–50%** of all cases. Minor salivary glands are distributed throughout the upper aerodigestive tract, but their highest density is found at the junction of the hard and soft palate. **Analysis of Options:** * **B. Palate (Correct):** Due to the high concentration of minor salivary tissue, the palate is the primary site. A key clinical feature of minor salivary gland tumors is that they are more likely to be **malignant** (approx. 50%) compared to parotid tumors (approx. 20%). * **A. Cheek (Buccal Mucosa):** While minor glands exist here, tumors are significantly less common than in the palate. * **C. Sublingual Gland:** This is a **major** salivary gland, not a minor one. Although rare, tumors here have an extremely high malignancy rate (80%). * **D. Tongue:** Tumors can occur at the base or lateral borders (associated with glands of Von Ebner), but the frequency is much lower than the palatal site. **High-Yield Clinical Pearls for NEET-PG:** 1. **Most common minor salivary gland tumor:** Adenoid Cystic Carcinoma (overall, though Pleomorphic Adenoma is the most common benign type). 2. **Rule of 80s (Salivary Glands):** 80% of tumors are in the Parotid; 80% of Parotid tumors are Pleomorphic Adenoma; 80% are in the superficial lobe. 3. **Malignancy Risk:** The smaller the gland, the higher the risk of malignancy (Sublingual > Submandibular > Parotid). 4. **Adenoid Cystic Carcinoma:** Characterized by **perineural invasion** and a "Swiss-cheese" appearance on histology.

Question 74: What is perimolysis?

A. Tooth wear due to gastric secretion (Correct Answer)
B. Tooth wear due to bruxism
C. Tooth wear due to dentifrices
D. Peripheral blood cell destruction

Explanation: **Explanation:** **Perimolysis** (also known as dental erosion) refers to the irreversible loss of dental hard tissue due to a chemical process involving extrinsic or intrinsic acids, without bacterial involvement. 1. **Why Option A is Correct:** Perimolysis is specifically associated with **intrinsic acid**—namely, gastric hydrochloric acid (pH 1–2). When gastric contents enter the oral cavity, the acid chemically dissolves the hydroxyapatite crystals of the enamel. This is most commonly seen in patients with **GERD (Gastroesophageal Reflux Disease)** or eating disorders like **Bulimia Nervosa** (due to self-induced vomiting). The erosion typically affects the **palatal surfaces** of the maxillary teeth. 2. **Why the Other Options are Incorrect:** * **Option B (Bruxism):** This causes **Attrition**, which is tooth-to-tooth wear due to mechanical grinding or clenching. * **Option C (Dentifrices):** Tooth wear caused by external mechanical objects (like abrasive toothpastes or hard toothbrushes) is termed **Abrasion**. * **Option D (Peripheral blood cell destruction):** This is a hematological process (e.g., hemolysis) and is unrelated to dental pathology. **High-Yield Clinical Pearls for NEET-PG:** * **Patterns of Wear:** * *Attrition:* Incisal/occlusal surfaces. * *Abrasion:* Cervical/gingival margins. * *Perimolysis:* Palatal/lingual surfaces (classic sign of Bulimia). * **Sialadenosis:** Chronic, bilateral, non-inflammatory swelling of the parotid glands is often seen in bulimic patients alongside perimolysis. * **Management:** Treatment involves addressing the underlying gastric cause and using fluoride rinses to remineralize enamel; immediate brushing after acid exposure should be avoided as it accelerates wear.

Question 75: All of the following statements about lymphoepithelioma of the parotid gland are true, except:

A. Parotid gland is the most common site of lymphoepithelioma in the head and neck region (Correct Answer)
B. It is associated with EBV infection
C. It is highly radiosensitive
D. It is a type of squamous cell carcinoma

Explanation: **Explanation:** **1. Why Option A is the correct answer (The Exception):** Lymphoepithelioma (also known as Lymphoepithelioma-like carcinoma) is most commonly found in the **Nasopharynx**. While it can occur in the salivary glands (most frequently the parotid), it is a rare site compared to the nasopharynx. Therefore, the statement that the parotid is the most common site in the head and neck is incorrect. **2. Analysis of other options:** * **Option B (Associated with EBV):** This is true. Similar to nasopharyngeal carcinoma, lymphoepithelioma of the salivary glands shows a strong oncogenic association with the **Epstein-Barr Virus (EBV)**, particularly in specific ethnic groups like Eskimos and Southern Chinese populations. * **Option C (Highly Radiosensitive):** This is true. These tumors are characterized by a dense lymphoid stroma which makes them exquisitely sensitive to radiotherapy, often making it a primary or adjuvant treatment modality. * **Option D (Type of Squamous Cell Carcinoma):** This is true. Histologically, lymphoepithelioma is classified as an **undifferentiated squamous cell carcinoma** accompanied by a prominent non-neoplastic lymphocytic infiltrate. **Clinical Pearls for NEET-PG:** * **Most common benign parotid tumor:** Pleomorphic Adenoma. * **Most common malignant parotid tumor:** Mucoepidermoid Carcinoma. * **Warthin’s Tumor:** Also contains lymphoid tissue but is benign and associated with smoking. * **Lymphoepithelioma-like carcinoma (LELC):** When found in the parotid, it often presents as a firm, painless mass and has a better prognosis than other high-grade salivary carcinomas due to its radiosensitivity.

Question 76: All of the following are true about Mucoepidermoid carcinoma except -

A. Invades the facial nerve
B. Greater the mucin-producing cells, more malignant is the behavior (Correct Answer)
C. Behave like benign tumors in major salivary glands
D. Facial nerve preservation can be considered in low-grade tumors

Explanation: **Explanation:** Mucoepidermoid carcinoma (MEC) is the most common malignant tumor of the salivary glands. Its behavior is determined by its histological grading, which is based on the ratio of cell types. **Why Option B is the correct answer (False statement):** MEC is composed of three cell types: **Mucin-producing**, **Intermediate**, and **Epidermoid (squamous)** cells. In histological grading, a higher proportion of mucin-secreting cells indicates a **low-grade (well-differentiated)** tumor, which carries a better prognosis. Conversely, a predominance of epidermoid cells and cellular atypia signifies a high-grade, more aggressive malignancy. Therefore, more mucin-producing cells mean *less* malignant behavior. **Analysis of other options:** * **Option A:** High-grade MEC is aggressive and frequently invades local structures, including the **facial nerve**, leading to paralysis. * **Option C:** Low-grade MECs often present as slow-growing, painless masses that clinically mimic benign tumors (like Pleomorphic Adenoma), especially in the parotid gland. * **Option D:** In low-grade tumors where the facial nerve is not involved by the disease, **nerve preservation** is the standard of care during surgical excision (Parotidectomy). **High-Yield Clinical Pearls for NEET-PG:** * **Most common site:** Parotid gland (Major); Palate (Minor). * **Most common radiation-induced** salivary gland malignancy. * **Most common salivary gland malignancy in children.** * **Grading System:** Often uses the **AFIP (Armed Forces Institute of Pathology)** or Brandwein scoring system. * **Staining:** Mucin-producing cells can be highlighted using **Mucicarmine** or PAS stain.

Question 77: A 40-year-old female presented with bilateral parotid gland enlargement, dry eyes, dry mouth, chronic non-productive cough, and shortness of breath. On examination, hepatosplenomegaly was noted. CT scan of the chest and salivary gland biopsy were performed. Which of the following interleukins is involved in the pathogenesis of this disease?

A. IL-17
B. IL-18 (Correct Answer)
C. IL-15
D. IL-10

Explanation: ### **Explanation** **Diagnosis: Sarcoidosis (Heerfordt-Waldenström Syndrome variant)** The clinical presentation of bilateral parotid enlargement, sicca symptoms (dry eyes/mouth), hepatosplenomegaly, and respiratory symptoms (cough/dyspnea) strongly suggests **Sarcoidosis**. While these symptoms overlap with Sjögren’s syndrome, the systemic involvement (hepatosplenomegaly and lung symptoms) in a 40-year-old female points toward Sarcoidosis. **Why IL-18 is the Correct Answer:** Sarcoidosis is a multisystem granulomatous disease driven by a **Th1-polarized immune response**. * **IL-18** (Interferon-gamma inducing factor) is a potent pro-inflammatory cytokine produced by macrophages within the sarcoid granulomas. * It works synergistically with **IL-12** to stimulate T-cells and NK cells to produce **IFN-γ**, which is crucial for granuloma formation and maintenance. Elevated levels of IL-18 are found in the serum and bronchoalveolar lavage (BAL) fluid of patients with active sarcoidosis. **Analysis of Incorrect Options:** * **IL-17:** Associated with Th17 responses. While it plays a role in some autoimmune conditions (like Psoriasis or Ankylosing Spondylitis), it is not the primary driver in the classic Th1-mediated pathogenesis of Sarcoidosis. * **IL-15:** Involved in T-cell proliferation and NK cell survival, but not a specific hallmark of sarcoid granulomatous inflammation. * **IL-10:** An **anti-inflammatory** cytokine. It usually inhibits the production of Th1 cytokines. In sarcoidosis, a deficiency or imbalance of IL-10 may actually allow the pro-inflammatory response to persist. **High-Yield Clinical Pearls for NEET-PG:** * **Heerfordt’s Syndrome (Uveoparotid Fever):** A specific form of sarcoidosis characterized by Parotid enlargement, Facial nerve palsy, Uveitis, and Fever. * **Panda Sign:** Symmetrical uptake in the lacrimal and parotid glands on Gallium-67 scan (classic for sarcoidosis). * **Biopsy Gold Standard:** Shows **non-caseating granulomas** with Schaumann bodies and Asteroid bodies. * **Kveim-Siltzbach Test:** An older skin test for sarcoidosis (now largely replaced by ACE levels and imaging).

Question 78: What is the most likely consequence of a sialolith (salivary stone) in the excretory duct?

A. Chronic sialadenitis
B. Mucous retention cyst (Correct Answer)
C. Pleomorphic adenoma
D. Rupture of the duct

Explanation: **Explanation:** The correct answer is **B. Mucous retention cyst**. **Mechanism of Action:** A sialolith (salivary stone) acts as a physical obstruction within the excretory duct. When the duct is partially or completely blocked, the saliva produced by the gland cannot be drained. This leads to the accumulation of secretions, causing the duct to dilate. Because the accumulated fluid is lined by the **ductal epithelium**, it results in a **mucous retention cyst**. This is distinct from a mucous extravasation cyst (mucocele), which occurs due to ductal trauma and lacks an epithelial lining. **Analysis of Incorrect Options:** * **A. Chronic sialadenitis:** While long-standing obstruction can lead to inflammation and secondary infection (sialadenitis), the *direct and immediate* anatomical consequence of a ductal block is the formation of a retention cyst. Sialadenitis is a potential complication rather than the primary structural result. * **C. Pleomorphic adenoma:** This is a benign neoplasm of the salivary glands. It is caused by genetic mutations and cellular proliferation, not by mechanical obstruction or stones. * **D. Rupture of the duct:** While high pressure can theoretically occur, the ductal system is resilient. Obstruction typically leads to proximal dilatation (cyst formation) or glandular atrophy rather than an acute rupture. **High-Yield NEET-PG Pearls:** * **Most common site for Sialolithiasis:** Submandibular gland (80%), specifically in **Wharton’s duct**, due to the alkaline pH, high calcium content, and the upward (antigravity) course of the duct. * **Clinical Presentation:** Recurrent post-prandial pain and swelling (Mealtime syndrome). * **Investigation of Choice:** Non-contrast CT (NCCT) is highly sensitive; however, for radiolucent stones, Sialography or Ultrasound may be used. * **Ranula:** A specific type of mucous extravasation cyst occurring in the floor of the mouth, usually arising from the sublingual gland.

Question 79: All of the following are true about Ranula except:

A. Asymptomatic
B. Retention cyst
C. Premalignant (Correct Answer)
D. Occurs commonly on the floor of the mouth

Explanation: **Explanation:** A **Ranula** is a clinical term used to describe a translucent, bluish, fluctuant swelling found specifically on the **floor of the mouth**. It is caused by the extravasation or retention of mucus from the **sublingual salivary gland**. 1. **Why "Premalignant" is the correct (False) statement:** A ranula is a purely benign, reactive, or obstructive inflammatory lesion. It is **not premalignant** and has no potential for neoplastic transformation. Any suspicion of malignancy in a floor-of-the-mouth swelling should lead to a differential diagnosis of a salivary gland tumor (like Mucoepidermoid carcinoma), but the ranula itself is benign. 2. **Analysis of other options:** * **Asymptomatic (Option A):** Most ranulas are painless and slow-growing. They typically only cause symptoms if they become large enough to interfere with speech, swallowing, or mastication. * **Retention Cyst (Option B):** While many ranulas are "extravasation pseudocysts" (lacking an epithelial lining), they are classically categorized under the umbrella of **mucous retention phenomena** resulting from ductal obstruction or trauma to the sublingual gland. * **Floor of the Mouth (Option D):** This is the classic anatomical location. It arises lateral to the midline, distinguishing it from a dermoid cyst which is typically midline. **High-Yield Clinical Pearls for NEET-PG:** * **Plunging Ranula:** Occurs when the mucus extravasates through or around the **mylohyoid muscle**, presenting as a swelling in the submandibular neck region. * **Appearance:** Often described as "frog’s belly" appearance due to its translucent blue color. * **Treatment of Choice:** Surgical excision of the ranula along with the **offending sublingual gland**. Marsupialization is an alternative but has a higher recurrence rate.

Question 80: A 70-year-old male presented with an asymptomatic white patch on the oral cavity following the application of a denture. What is the treatment of choice?

A. Low dose radiotherapy
B. Biopsy of all the tissues
C. Ascertaining that the denture fits properly (Correct Answer)
D. Antibiotics

Explanation: ### Explanation The clinical presentation describes **Frictional Keratosis**, a common reactive lesion of the oral mucosa. In this 70-year-old patient, the white patch is likely a response to chronic mechanical irritation from an ill-fitting denture. **1. Why Option C is Correct:** The primary management of any white patch in the oral cavity is to **identify and eliminate the causative factor**. Frictional keratosis is a protective hyperkeratotic response (similar to a callus on the skin). If the lesion is caused by a mechanical trigger like a sharp tooth or an ill-fitting denture, the first line of treatment is to adjust or replace the prosthesis. If the lesion resolves after removing the irritant (usually within 2–4 weeks), no further intervention is needed. **2. Why Other Options are Incorrect:** * **Option A (Radiotherapy):** This is contraindicated. Radiotherapy is used for malignancies, not for benign reactive hyperkeratosis. It can also induce further mucosal damage (mucositis) or malignant transformation. * **Option B (Biopsy of all tissues):** While a biopsy is mandatory for "idiopathic" leukoplakia or if a lesion persists after removing the irritant, it is not the *immediate* first step for a lesion with a clear mechanical cause. * **Option D (Antibiotics):** White patches (keratosis) are structural changes in the epithelium, not acute bacterial infections. Antibiotics have no role here. **Clinical Pearls for NEET-PG:** * **Leukoplakia vs. Frictional Keratosis:** Leukoplakia is a "diagnosis of exclusion" and is potentially premalignant. Frictional keratosis has a known cause and is generally considered a benign reactive process. * **The 2-Week Rule:** Any oral white patch that persists for more than 14 days after the removal of local irritants must undergo a biopsy to rule out dysplasia or squamous cell carcinoma. * **Common Sites:** Frictional keratosis is most commonly seen on the buccal mucosa (linea alba), lateral tongue, and edentulous ridges.

Practice by Chapter

Stomatitis

Practice Questions

Oral Ulcers

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Oral Leukoplakia

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Oral Cancers

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Sialadenitis

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Sialolithiasis

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Salivary Gland Tumors

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Ranula

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Xerostomia

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Sjögren's Syndrome

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Oral Manifestations of Systemic Diseases

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Temporomandibular Joint Disorders

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