Diseases of the Oral Cavity and Salivary Glands Practice Questions

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

Biopsy can confirm the diagnosis. **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.

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

Systemic lupus erythematosus (SLE). **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.

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

Palate. **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.

Q: What is perimolysis?

Tooth wear due to gastric secretion. **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.

Q: All of the following are true about Ranula except:

Premalignant. **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 1

How can tuberculosis be easily differentiated from squamous cell carcinoma?

Accepted Answer

Biopsy can confirm the diagnosis

Answer

Acid-fast bacilli positive with Ziehl-Neelsen stain

Answer

Primary lesion occurs on the tongue

Answer

Direct smear examination

Question 2

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

Accepted Answer

Systemic lupus erythematosus (SLE)

Answer

Sjogren's syndrome

Answer

Sarcoidosis

Answer

Chronic pancreatitis

Question 3

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

Accepted Answer

Palate

Answer

Cheek

Answer

Sublingual gland

Answer

Tongue

Question 4

What is perimolysis?

Accepted Answer

Tooth wear due to gastric secretion

Answer

Tooth wear due to bruxism

Answer

Tooth wear due to dentifrices

Answer

Peripheral blood cell destruction

Question 5

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

Accepted Answer

Parotid gland is the most common site of lymphoepithelioma in the head and neck region

Answer

It is associated with EBV infection

Answer

It is highly radiosensitive

Answer

It is a type of squamous cell carcinoma

Question 6

All of the following are true about Mucoepidermoid carcinoma except -

Accepted Answer

Greater the mucin-producing cells, more malignant is the behavior

Answer

Invades the facial nerve

Answer

Behave like benign tumors in major salivary glands

Answer

Facial nerve preservation can be considered in low-grade tumors

Question 7

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?

Accepted Answer

IL-18

Answer

IL-17

Answer

IL-15

Answer

IL-10

Question 8

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

Accepted Answer

Mucous retention cyst

Answer

Chronic sialadenitis

Answer

Pleomorphic adenoma

Answer

Rupture of the duct

Question 9

All of the following are true about Ranula except:

Accepted Answer

Premalignant

Answer

Asymptomatic

Answer

Retention cyst

Answer

Occurs commonly on the floor of the mouth

Question 10

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?

Accepted Answer

Ascertaining that the denture fits properly

Answer

Low dose radiotherapy

Answer

Biopsy of all the tissues

Answer

Antibiotics

Diseases of the Oral Cavity and Salivary Glands — MCQs

Diseases of the Oral Cavity and Salivary Glands — MCQs

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