ABPath Dermatopathology 2

Question 1

Which vasculitis is most strongly associated with c-ANCA (PR3-ANCA) and shows necrotizing granulomatous inflammation of small vessels?

Accepted Answer

Granulomatosis with polyangiitis (Wegener)

Answer

Granulomatosis with polyangiitis (formerly Wegener's) is a small-vessel vasculitis strongly associated with c-ANCA/PR3-ANCA and shows necrotizing granulomatous inflammation affecting the upper airway, lungs, and kidneys.

Question 2

A skin biopsy shows a perivascular lymphoplasmacytic infiltrate and spirochetes on Warthin-Starry stain. This is most consistent with:

Accepted Answer

Secondary syphilis

Answer

Secondary syphilis shows lichenoid or superficial/deep perivascular infiltrate with prominent plasma cells; Treponema pallidum spirochetes can be demonstrated with Warthin-Starry or immunohistochemical stains.

Question 3

Which syndrome links multiple sebaceous adenomas/carcinomas to internal malignancies (especially colorectal cancer) through mismatch repair gene mutations?

Accepted Answer

Muir-Torre syndrome

Answer

Muir-Torre syndrome is a variant of Lynch syndrome caused by mismatch repair gene mutations (MLH1, MSH2), characterized by sebaceous neoplasms and an increased risk of visceral malignancies.

Question 4

Concentric 'onion skin' periductal fibrosis around eccrine sweat glands on skin biopsy is most characteristic of:

Accepted Answer

Systemic sclerosis (scleroderma)

Answer

Systemic sclerosis (scleroderma) characteristically shows concentric periductal fibrosis around eccrine glands and replacement of deep dermis/subcutaneous fat with densely packed collagen.

Question 5

A biopsy shows suprabasilar acantholysis with basal cells remaining attached to the basement membrane ('tombstoning'). This pattern is diagnostic of:

Accepted Answer

Pemphigus vulgaris

Answer

Pemphigus vulgaris shows suprabasilar acantholysis with 'tombstoning' of single basal cells still attached to the basement membrane, forming intraepidermal blisters due to anti-desmoglein 3 autoantibodies.

American Board of Pathology (ABPath) Practice Test

American Board of Pathology (ABPath) Practice Test

ABPath Dermatopathology 2