Question

Which special stain is used to demonstrate fibrosis (collagen deposition) in a liver biopsy?

• A. Masson trichrome
• B. Periodic acid-Schiff (PAS)
• C. Gomori methenamine silver (GMS)
• D. Gram stain

Hint:

Which dye method turns collagen blue/green?

Answer 1

The Correct Option is A

Step 1: Identify what is being asked.
The slides show liver fibrosis, and the question asks which stain best demonstrates the deposited collagen.

Step 2: Recall Masson trichrome.
Masson trichrome is a three-dye method that stains collagen and fibrous connective tissue blue or green, muscle/cytoplasm and keratin red, and nuclei dark blue/black. It is the standard stain to highlight and stage fibrosis (e.g., bridging fibrosis, cirrhosis) in liver biopsies.

Step 3: Eliminate the wrong options.
PAS stains glycogen, basement membranes and fungal walls magenta (PAS with diastase highlights alpha-1-antitrypsin globules, not fibrosis). GMS (Gomori methenamine silver) is a fungal/Pneumocystis and basement-membrane stain. Gram stain is for bacteria. None of these selectively demonstrate collagen.

Key fact: Collagen/fibrosis is best shown by Masson trichrome (and reticulin for the collapse pattern).