CDT Laboratory Procedures & Biopsies 3 — Questions and Answers
Question 1: When labeling a biopsy specimen container, which information is MOST critical to include?
- Patient's insurance information
- Patient name, date of birth, and biopsy site (Correct answer)
- Physician's license number
- Time of day the biopsy was performed
Correct answer: Patient name, date of birth, and biopsy site
Patient name, date of birth, and biopsy site are essential identifiers to ensure correct specimen-patient matching and accurate pathology reporting.
Question 2: Which stain is used in dermatopathology to highlight mast cells?
- Hematoxylin and eosin (H&E)
- Toluidine blue (Correct answer)
- Periodic acid-Schiff (PAS)
- Gomori methenamine silver (GMS)
Correct answer: Toluidine blue
Toluidine blue stains mast cell granules metachromatically (purple-red), making it the preferred stain for identifying mast cells in tissue sections.
Question 3: A patient presents with a nodule on the ear. The dermatologist requests an incisional biopsy. What does this technique involve?
- Removal of the entire lesion with clear margins
- Removal of only a representative portion of the lesion (Correct answer)
- Scraping the surface of the lesion
- Using a hollow punch to remove a core sample
Correct answer: Removal of only a representative portion of the lesion
An incisional biopsy removes only part of a larger lesion for diagnosis when complete excision is not practical or necessary at the initial visit.
Question 4: What is the purpose of the Wood's lamp examination in a dermatology laboratory setting?
- To measure skin thickness
- To detect UV-fluorescent organisms or pigmentation changes (Correct answer)
- To perform dermoscopy
- To test skin sensitivity to allergens
Correct answer: To detect UV-fluorescent organisms or pigmentation changes
Wood's lamp emits long-wave UV light (365 nm) that causes certain fungi, bacteria, and pigmentary conditions to fluoresce, aiding in diagnosis.
Question 5: Which local anesthetic is most commonly used for skin biopsy procedures?
- Bupivacaine 0.5%
- Lidocaine 1% with or without epinephrine (Correct answer)
- Tetracaine 0.5%
- Ropivacaine 0.2%
Correct answer: Lidocaine 1% with or without epinephrine
Lidocaine 1% with epinephrine is the standard choice for skin biopsies because it provides rapid onset anesthesia and vasoconstriction to minimize bleeding.
Question 6: After a punch biopsy, the wound is typically closed with which suture technique?
- Mattress suture
- Running subcuticular suture
- Single interrupted suture (Correct answer)
- Figure-of-eight suture
Correct answer: Single interrupted suture
A single interrupted suture (or two) is standard for closing small punch biopsy wounds due to the small defect size and ease of placement.
Question 7: When is it appropriate to use a shave biopsy?
- Deep nodular lesions requiring subcutaneous tissue
- Suspected melanoma requiring depth measurement
- Superficial raised lesions like seborrheic keratoses or nevi above the skin plane (Correct answer)
- Nail matrix biopsies
Correct answer: Superficial raised lesions like seborrheic keratoses or nevi above the skin plane
Shave biopsies are appropriate for superficial, raised lesions because they cleanly remove the elevated portion without requiring sutures.
CDT Laboratory Procedures & Biopsies 3
When labeling a biopsy specimen container, which information is MOST critical to include?