Pathology · single question
What type of biopsy is used for the diagnosis of Mucous Membrane Pemphigoid (MMP)?
Show answer and explanation
Correct answer: A. Incisional biopsy (with perilesional tissue for direct immunofluorescence)
✓ A) Incisional biopsy is correct.
MMP diagnosis requires: (1) incisional biopsy of PERILESIONAL tissue (not the ulcerated/bullous area itself — it's already degraded); (2) submitted for direct immunofluorescence (DIF) which shows LINEAR deposits of IgG and/or C3 along the basement membrane zone. This linear BMZ pattern distinguishes MMP from pemphigus (which shows intercellular/fishnet IgG pattern). Cytology smears cannot diagnose MMP. Excisional biopsy is not appropriate for diagnostic purposes in MMP.
MMP diagnosis requires: (1) incisional biopsy of PERILESIONAL tissue (not the ulcerated/bullous area itself — it's already degraded); (2) submitted for direct immunofluorescence (DIF) which shows LINEAR deposits of IgG and/or C3 along the basement membrane zone. This linear BMZ pattern distinguishes MMP from pemphigus (which shows intercellular/fishnet IgG pattern). Cytology smears cannot diagnose MMP. Excisional biopsy is not appropriate for diagnostic purposes in MMP.