Pathology · patient case question
What would be useful in confirming the diagnosis?
Patient case: Pemphigus vulgaris — confirming the diagnosis
Scenario: A case in which the diagnosis of PEMPHIGUS VULGARIS is given.
Show answer and explanation
Correct answer: A. Immunofluorescence
- A. Correct. IMMUNOFLUORESCENCE is the definitive test. DIRECT immunofluorescence on perilesional tissue shows IgG and C3 deposited in a 'fishnet' or 'chicken-wire' pattern between the epithelial cells; INDIRECT immunofluorescence on serum detects circulating anti-desmoglein antibodies, whose titre tracks disease activity.
- B. Excisional biopsy is for small discrete lesions and does not provide the immunologic information needed here.
- C. Brush biopsy samples surface cells only and cannot demonstrate the level of the split or the antibody deposition pattern.
- D. Exfoliative cytology may show acantholytic TZANCK CELLS, which is suggestive, but it is not diagnostic and cannot distinguish pemphigus from viral acantholysis.