CDT Laboratory Procedures & Biopsies 2

Question 1

Which biopsy technique is most appropriate for sampling a large, flat, pigmented lesion to assess for melanoma?

Accepted Answer

Excisional biopsy

Answer

Excisional biopsy removes the entire lesion with margins, providing complete tissue for accurate melanoma staging and Breslow depth measurement.

Question 2

When performing a KOH (potassium hydroxide) preparation, what does a positive result indicate?

Accepted Answer

Fungal infection

Answer

KOH dissolves keratin, leaving fungal hyphae or spores visible under microscopy, confirming a fungal infection.

Question 3

What is the correct angle for inserting a punch biopsy tool into the skin?

Accepted Answer

90 degrees perpendicular to the skin surface

Answer

The punch biopsy tool should be inserted perpendicular (90°) to the skin surface while rotating to obtain a cylindrical core of tissue.

Question 4

Which fixative is the standard for preserving biopsy specimens before histopathologic analysis?

Accepted Answer

10% neutral buffered formalin

Answer

10% neutral buffered formalin is the standard tissue fixative because it preserves cellular architecture and is compatible with most histologic stains.

Question 5

A slit-skin smear is primarily used to diagnose which condition?

Accepted Answer

Leprosy

Answer

Slit-skin smears are used to detect Mycobacterium leprae in tissue fluid from incised skin sites to diagnose and classify leprosy.

(CDT) Certified Dermatology Tech Practice Test

(CDT) Certified Dermatology Tech Practice Test

CDT Laboratory Procedures & Biopsies 2