Dermatologist Certificate Dermatological Procedures and Treatments 1 — Questions and Answers
Question 1: What is the recommended surgical margin for a primary melanoma with Breslow thickness between 1.01–2.0 mm?
- 1–2 cm wide local excision (Correct answer)
- 0.5 cm wide local excision
- 3 cm wide local excision
- 5 mm punch excision
Correct answer: 1–2 cm wide local excision
Current guidelines recommend 1–2 cm surgical margins for melanomas with Breslow thickness between 1.01 and 2.0 mm to achieve adequate local control.
Question 2: Mohs micrographic surgery is most appropriate for which type of skin cancer?
- High-risk basal cell carcinoma on the face with poorly defined borders (Correct answer)
- Thin superficial spreading melanoma on the trunk
- Dermatofibrosarcoma protuberans on the scalp
- Sebaceous carcinoma on the eyelid
Correct answer: High-risk basal cell carcinoma on the face with poorly defined borders
Mohs surgery is the gold standard for high-risk BCCs, particularly on the face (H-zone), with recurrent tumors, or poorly defined borders where tissue conservation is critical.
Question 3: Which phototherapy modality delivers narrowband ultraviolet B (NB-UVB) radiation at approximately 311–313 nm?
- Narrowband UVB lamp (Correct answer)
- PUVA (psoralen + UVA)
- Excimer laser
- Broadband UVB
Correct answer: Narrowband UVB lamp
Narrowband UVB phototherapy uses a fluorescent lamp that emits UVB radiation at the therapeutic peak of 311–313 nm, which is more effective and safer than broadband UVB.
Question 4: What is the mechanism of action of cryotherapy in treating actinic keratoses?
- Rapid freezing causes intracellular ice crystal formation and cell destruction (Correct answer)
- Chemical destruction of the stratum corneum
- Selective thermolysis of pigmented cells
- Thermal denaturaÂtion of keratin proteins
Correct answer: Rapid freezing causes intracellular ice crystal formation and cell destruction
Cryotherapy destroys abnormal cells through rapid freezing with liquid nitrogen, causing intracellular ice crystal formation, membrane disruption, and subsequent cell death.
Question 5: Which laser type is considered the gold standard for treating port-wine stains?
- Pulsed dye laser (585/595 nm) (Correct answer)
- Q-switched Nd:YAG laser
- Fractional CO2 laser
- Alexandrite laser
Correct answer: Pulsed dye laser (585/595 nm)
The pulsed dye laser, which targets oxyhemoglobin at 585 or 595 nm, is the treatment of choice for port-wine stains and other vascular lesions using the principle of selective photothermolysis.
Question 6: What is the recommended first-line topical treatment for localized superficial basal cell carcinoma?
- Imiquimod 5% cream (Correct answer)
- 5-fluorouracil cream
- Diclofenac gel
- Tretinoin cream
Correct answer: Imiquimod 5% cream
Imiquimod 5% cream is FDA-approved for superficial BCC and works as an immune response modifier stimulating innate and adaptive immunity against tumor cells.
Dermatologist Certificate Dermatological Procedures and Treatments 1
What is the recommended surgical margin for a primary melanoma with Breslow thickness between 1.01–2.0 mm?