INBDE Oral Medicine and Oral Pathology 2 — Questions and Answers
Question 1: Which odontogenic cyst has the highest recurrence rate due to an aggressive, thin-walled epithelial lining that produces keratin?
- Dentigerous cyst
- Radicular cyst
- Odontogenic keratocyst (Correct answer)
- Nasopalatine duct cyst
Correct answer: Odontogenic keratocyst
The odontogenic keratocyst (OKC) has a high recurrence rate (25–60%) because its thin, friable parakeratinized epithelial lining is prone to incomplete removal and satellite cyst formation.
Question 2: A patient presents with multiple basal cell carcinomas, calcified falx cerebri, and odontogenic keratocysts of the jaw. What syndrome is present?
- Cowden syndrome
- Gorlin-Goltz syndrome (Correct answer)
- Gardner syndrome
- Peutz-Jeghers syndrome
Correct answer: Gorlin-Goltz syndrome
Gorlin-Goltz (nevoid basal cell carcinoma) syndrome is characterized by multiple OKCs of the jaws, basal cell nevi/carcinomas, and calcification of the falx cerebri.
Question 3: Which type of lichen planus carries the highest risk of malignant transformation?
- Reticular lichen planus
- Erosive lichen planus (Correct answer)
- Papular lichen planus
- Plaque-type lichen planus
Correct answer: Erosive lichen planus
Erosive (atrophic/ulcerative) lichen planus has the greatest malignant potential among lichen planus variants, with an estimated 0.5–2% risk of transformation to squamous cell carcinoma.
Question 4: A painless, slow-growing mass at the angle of the mandible in a 60-year-old is found to contain perineural invasion on biopsy. Which salivary gland tumor is most likely?
- Pleomorphic adenoma
- Warthin's tumor
- Adenoid cystic carcinoma (Correct answer)
- Acinic cell carcinoma
Correct answer: Adenoid cystic carcinoma
Adenoid cystic carcinoma is notorious for perineural invasion and spread, explaining pain or facial nerve symptoms despite its deceptively slow growth.
Question 5: Which bone disease presents radiographically as a 'ground glass' or 'orange peel' appearance and results from replacement of normal bone with fibrous connective tissue?
- Paget's disease of bone
- Fibrous dysplasia (Correct answer)
- Cherubism
- Langerhans cell histiocytosis
Correct answer: Fibrous dysplasia
Fibrous dysplasia replaces normal medullary bone with fibrous connective tissue containing woven bone trabeculae, producing the classic ground-glass radiographic pattern.
Question 6: A 5-year-old child presents with bilateral jaw swelling causing an upward gaze appearance. Radiographs show multilocular radiolucencies. What is the most likely diagnosis?
- Fibrous dysplasia
- Cherubism (Correct answer)
- Osteosarcoma
- Giant cell granuloma
Correct answer: Cherubism
Cherubism is an autosomal dominant condition causing bilateral fibrous replacement of jaw bone in childhood, producing multilocular radiolucencies and the characteristic upward gaze due to orbital floor involvement.
Question 7: Pemphigus vulgaris is caused by autoantibodies directed against which target?
- Laminin-332
- Type VII collagen
- Desmoglein 3 (Correct answer)
- BP180 (BPAG2)
Correct answer: Desmoglein 3
Pemphigus vulgaris results from IgG autoantibodies against desmoglein 3 (and desmoglein 1 in skin involvement), disrupting keratinocyte adhesion and causing intraepithelial blistering.
INBDE Oral Medicine and Oral Pathology 2
Which odontogenic cyst has the highest recurrence rate due to an aggressive, thin-walled epithelial lining that produces keratin?