ADC - Australian Dental Council Oral Medicine and Pathology Questions and Answers — Questions and Answers
Question 1: A 48-year-old female patient presents with asymptomatic, bilateral, white, lace-like lesions on her buccal mucosa. She has no other medical history of note. The lesions do not rub off on examination. What is the most likely diagnosis?
- Oral Candidiasis
- Leukoplakia
- Reticular Oral Lichen Planus (Correct answer)
- Linea Alba
Correct answer: Reticular Oral Lichen Planus
The description of bilateral, asymptomatic, white, lace-like (reticular) striae on the buccal mucosa is the classic presentation of reticular oral lichen planus. Oral candidiasis typically presents as white plaques that can be wiped off, often leaving an erythematous base. Leukoplakia is a clinical term for a white patch that is not attributable to another disease and is typically unilateral. Linea alba is a benign frictional keratosis that corresponds precisely to the occlusal plane.
Question 2: A 62-year-old female patient complains of a persistent dry mouth and a 'gritty' sensation in her eyes for the past year. Clinical examination reveals a lobulated tongue with papillary atrophy and bilateral, firm, non-tender swelling of the parotid glands. She has a high caries rate despite good oral hygiene. Which systemic autoimmune condition is most likely responsible for these findings?
- Sjögren's Syndrome (Correct answer)
- Systemic Lupus Erythematosus (SLE)
- Rheumatoid Arthritis
- Sarcoidosis
Correct answer: Sjögren's Syndrome
The combination of xerostomia (dry mouth) and xerophthalmia (dry eyes), known as sicca syndrome, along with bilateral salivary gland enlargement, is the hallmark of Sjögren's Syndrome. The resulting severe hyposalivation also explains the high caries rate. While patients with SLE or Rheumatoid Arthritis can have secondary Sjögren's, the primary presentation described points directly to this diagnosis. Sarcoidosis can cause parotid swelling, but the prominent sicca symptoms are more characteristic of Sjögren's.
Question 3: A large, multilocular radiolucency is noted in the posterior mandible of a 25-year-old male, extending into the ramus. A biopsy is performed. Which of the following histopathological features is most characteristic of an Odontogenic Keratocyst (OKC)?
- Presence of ghost cells and dystrophic calcification
- A thin, uniform parakeratinised epithelial lining with a palisaded, hyperchromatic basal cell layer (Correct answer)
- Mucous-producing cells and pools of mucin
- An inflamed fibrous capsule with prominent, arcading rete ridges
Correct answer: A thin, uniform parakeratinised epithelial lining with a palisaded, hyperchromatic basal cell layer
The histopathological hallmark of an OKC is its unique epithelial lining. It is typically thin and uniform (around 5-8 cells thick), parakeratinised, and features a prominent, palisaded basal cell layer composed of hyperchromatic (darkly stained) columnar or cuboidal cells. Ghost cells are characteristic of Calcifying Odontogenic Cysts (Gorlin cyst). Mucous cells are found in Glandular Odontogenic Cysts or Mucoepidermoid Carcinomas. An inflamed capsule with arcading rete ridges is typical of an inflammatory cyst like a radicular cyst.
Question 4: In the context of developing oral squamous cell carcinoma (OSCC), what is the significance of a patient's combined heavy smoking and alcohol consumption habits?
- They are independent risk factors with no interactive effect.
- Alcohol is the primary carcinogen, and tobacco is a minor promoter.
- They have a synergistic effect, significantly increasing the risk more than the sum of their individual effects. (Correct answer)
- Tobacco is the primary carcinogen, and alcohol has no proven effect on risk.
Correct answer: They have a synergistic effect, significantly increasing the risk more than the sum of their individual effects.
Tobacco and alcohol are the two most significant risk factors for OSCC. Their combined use has a synergistic effect, meaning the total risk is much greater (up to 30-fold) than the additive risk of using either substance alone. Alcohol is thought to act as a solvent, increasing the permeability of the oral mucosa to the carcinogens found in tobacco smoke.
Question 5: A 65-year-old patient presents with painful, desquamating gingivitis and several intact bullae on the soft palate. Gentle lateral pressure on the clinically unaffected gingiva results in the formation of a new blister. What is this clinical sign called, and with which group of conditions is it most strongly associated?
- Auspitz's sign; Psoriasis
- Wickham's striae; Oral Lichen Planus
- Darier's sign; Mastocytosis
- Nikolsky's sign; Autoimmune blistering diseases (Correct answer)
Correct answer: Nikolsky's sign; Autoimmune blistering diseases
Nikolsky's sign is the clinical phenomenon where the epithelium dislodges from the underlying tissue with slight rubbing or pressure. It is a characteristic finding in autoimmune blistering (vesiculobullous) diseases such as Pemphigus Vulgaris and Mucous Membrane Pemphigoid. Auspitz's sign relates to psoriasis, Wickham's striae are pathognomonic for lichen planus, and Darier's sign is associated with mastocytosis.
Question 6: A 70-year-old female patient, who has been receiving intravenous zoledronic acid for bone metastases from breast cancer for the past three years, requires extraction of a non-restorable mandibular molar. According to Australian guidelines and best practice, which of the following is the most significant oral complication this patient is at high risk of developing?
- Alveolar osteitis (dry socket)
- Medication-Related Osteonecrosis of the Jaw (MRONJ) (Correct answer)
- Post-operative cellulitis
- Excessive post-operative haemorrhage
Correct answer: Medication-Related Osteonecrosis of the Jaw (MRONJ)
The patient is taking a potent intravenous bisphosphonate (zoledronic acid) for a malignancy indication and has been on the therapy for over two years. This places her in a high-risk category for developing Medication-Related Osteonecrosis of the Jaw (MRONJ). Dentoalveolar surgery, such as an extraction, is a major precipitating factor for MRONJ. While the other options are general risks of extraction, MRONJ is the specific, severe complication directly related to her systemic medication and is the primary concern.
ADC - Australian Dental Council Oral Medicine and Pathology Questions and Answers
A 48-year-old female patient presents with asymptomatic, bilateral, white, lace-like lesions on her buccal mucosa.
She has no other medical history of note.
The lesions do not rub off on examination.
What is the most likely diagnosis?