NBDE Oral Pathology and Radiology 3 — Questions and Answers
Question 1: Geographic tongue (benign migratory glossitis) is characterized histologically by:
- Hyperparakeratosis with Candida hyphae
- Loss of filiform papillae with neutrophilic infiltration forming Munro microabscesses (Correct answer)
- Acantholysis with suprabasal clefting
- Dense subepithelial lymphocytic band
Correct answer: Loss of filiform papillae with neutrophilic infiltration forming Munro microabscesses
Geographic tongue shows atrophy of filiform papillae and neutrophilic spongiform pustules (Munro microabscesses) resembling psoriasis histologically.
Question 2: A child presents with a painless swelling at the angle of the mandible. CT shows a well-defined cystic lesion in the parotid region containing fat and skin appendages. The diagnosis is:
- Lymphoepithelial cyst
- Dermoid cyst (Correct answer)
- Brachial cleft cyst
- Pleomorphic adenoma
Correct answer: Dermoid cyst
A dermoid cyst contains ectodermal elements including hair follicles, sebaceous glands, and fat, differentiating it from epidermoid cysts which lack skin appendages.
Question 3: The 'condensing osteitis' (focal sclerosing osteomyelitis) seen on periapical films is best described as:
- Radiolucent halo around an apex of a non-vital tooth
- Diffuse radiopacity at the apex of a tooth with pulpitis or necrosis (Correct answer)
- Multilocular radiolucency replacing bone
- Corticated unilocular cyst at the apex
Correct answer: Diffuse radiopacity at the apex of a tooth with pulpitis or necrosis
Condensing osteitis is a bony reaction to low-grade pulpal inflammation that appears as a diffuse periapical radiopacity, most often at mandibular first molar apices.
Question 4: Sjögren syndrome causes xerostomia primarily due to:
- Ductal obstruction by sialoliths
- Lymphocytic infiltration and destruction of acinar cells (Correct answer)
- Autonomic neuropathy of salivary glands
- Fibrosis secondary to radiation therapy
Correct answer: Lymphocytic infiltration and destruction of acinar cells
In Sjögren syndrome, autoreactive T-cells infiltrate and destroy the secretory acinar cells of salivary and lacrimal glands, causing dry mouth and dry eyes.
Question 5: Which radiographic appearance best describes a periapical granuloma versus a radicular cyst?
- Granulomas are larger and have sclerotic borders; cysts are smaller
- Granulomas and cysts cannot be reliably differentiated radiographically (Correct answer)
- Granulomas are multilocular; cysts are unilocular
- Cysts appear radiopaque; granulomas appear radiolucent
Correct answer: Granulomas and cysts cannot be reliably differentiated radiographically
Periapical granulomas and radicular cysts both appear as periapical radiolucencies and cannot be definitively distinguished radiographically — histologic examination is required.
Question 6: Nevoid basal cell carcinoma syndrome (Gorlin syndrome) is associated with multiple odontogenic cysts of which type?
- Radicular cysts
- Dentigerous cysts
- Odontogenic keratocysts (keratocystic odontogenic tumors) (Correct answer)
- Lateral periodontal cysts
Correct answer: Odontogenic keratocysts (keratocystic odontogenic tumors)
Gorlin syndrome is characterized by multiple odontogenic keratocysts (now called keratocystic odontogenic tumors), basal cell carcinomas, calcified falx cerebri, and skeletal anomalies.
Question 7: A 60-year-old patient's panoramic radiograph shows a 'ground glass' generalized jaw opacity with loss of lamina dura and a 'cotton wool' appearance. This is classic for:
- Fibrous dysplasia
- Paget disease of bone (Correct answer)
- Hyperparathyroidism
- Osteopetrosis
Correct answer: Paget disease of bone
Paget disease of the jaw shows a late-stage 'cotton wool' mixed radiolucent-opaque pattern from disordered bone remodeling, with loss of lamina dura and hypercementosis.
NBDE Oral Pathology and Radiology 3
Geographic tongue (benign migratory glossitis) is characterized histologically by: