ABD Dermatopathology 3 — Questions and Answers
Question 1: A biopsy shows acantholysis with a 'row of tombstones' basal cell appearance and intraepidermal, suprabasal clefting. Which disease is this?
- Pemphigus vulgaris (Correct answer)
- Bullous pemphigoid
- Darier disease
- Hailey-Hailey disease
Correct answer: Pemphigus vulgaris
Suprabasal acantholysis leaving a 'row of tombstones' of basal keratinocytes is classic for pemphigus vulgaris.
Question 2: Direct immunofluorescence showing granular IgA deposits in the dermal papillae supports which diagnosis?
- Dermatitis herpetiformis (Correct answer)
- Bullous pemphigoid
- Linear IgA disease
- Pemphigus foliaceus
Correct answer: Dermatitis herpetiformis
Granular IgA in the dermal papillary tips is the hallmark of dermatitis herpetiformis.
Question 3: A cutaneous tumor shows peripheral palisading of basaloid cells with clefting (retraction) from the surrounding stroma. What is the diagnosis?
- Basal cell carcinoma (Correct answer)
- Squamous cell carcinoma
- Trichoepithelioma
- Merkel cell carcinoma
Correct answer: Basal cell carcinoma
Peripheral palisading of basaloid nests with stromal retraction artifact is characteristic of basal cell carcinoma.
Question 4: Which histologic finding is most characteristic of a Spitz nevus?
- Kamino bodies (Correct answer)
- Pautrier microabscesses
- Grenz zone
- Verocay bodies
Correct answer: Kamino bodies
Kamino bodies (eosinophilic PAS-positive globules at the junction) are characteristic of a Spitz nevus.
Question 5: Pautrier microabscesses (intraepidermal collections of atypical lymphocytes) are a diagnostic feature of which condition?
- Mycosis fungoides (Correct answer)
- Psoriasis
- Spongiotic dermatitis
- Lichen simplex chronicus
Correct answer: Mycosis fungoides
Pautrier microabscesses are clusters of atypical T-cells in the epidermis seen in mycosis fungoides (cutaneous T-cell lymphoma).
Question 6: A Fite (acid-fast) stain would be most useful in diagnosing which cutaneous infection?
- Leprosy (Hansen disease) (Correct answer)
- Syphilis
- Candidiasis
- Herpes simplex
Correct answer: Leprosy (Hansen disease)
The Fite stain is a modified acid-fast stain optimal for demonstrating Mycobacterium leprae.
Question 7: A dermal spindle-cell tumor stains diffusely positive for S-100 and SOX10 and shows wavy nuclei. Which tumor is most likely?
- Neurofibroma (Correct answer)
- Leiomyoma
- Dermatofibroma
- Kaposi sarcoma
Correct answer: Neurofibroma
S-100/SOX10-positive spindle cells with wavy 'comma-shaped' nuclei indicate neural differentiation, as in neurofibroma.
ABD Dermatopathology 3
A biopsy shows acantholysis with a 'row of tombstones' basal cell appearance and intraepidermal, suprabasal clefting.
Which disease is this?