NBDE Microbiology and Pathology 4

Question 1

A 60-year-old smoker presents with a white, non-scrapable lesion on the floor of the mouth. Biopsy shows severe epithelial dysplasia. The most appropriate management is:

Accepted Answer

Surgical excision with close follow-up

Answer

Severe dysplasia in a leukoplakia lesion carries high malignant transformation risk and requires surgical excision with surveillance.

Question 2

Which cytokine is primarily responsible for fever induction (endogenous pyrogen) in acute inflammatory responses?

Accepted Answer

IL-1β

Answer

IL-1β (along with TNF-α and IL-6) acts on the hypothalamus to raise the body's temperature set point via prostaglandin E2 production.

Question 3

A patient develops oral ulcers, genital ulcers, and uveitis. Which condition best explains this clinical triad?

Accepted Answer

Behçet disease

Answer

Behçet disease is characterized by recurrent oral aphthae, genital ulcers, and ocular inflammation (uveitis) and is associated with HLA-B51.

Question 4

Osteosarcoma of the jaw most commonly affects which anatomical location?

Accepted Answer

Posterior mandible/symphysis

Answer

Jaw osteosarcomas preferentially arise in the posterior body and symphysis of the mandible, occurring a decade later than long-bone osteosarcomas.

Question 5

Which immunoglobulin class is most abundant in saliva and serves as the primary mucosal defense against oral pathogens?

Accepted Answer

Secretory IgA (sIgA)

Answer

Secretory IgA is produced by plasma cells in salivary glands and combines with a secretory component that protects it from proteolytic degradation in saliva.

NBDE - National Board Dental Examination Practice Test

NBDE - National Board Dental Examination Practice Test

NBDE Microbiology and Pathology 4