Dermatologist Certificate Dermatopathology and Histology 2 — Questions and Answers
Question 1: Pautrier microabscesses on skin biopsy are characteristic of which condition?
- Psoriasis
- Atopic dermatitis
- Mycosis fungoides (Correct answer)
- Folliculitis decalvans
Correct answer: Mycosis fungoides
Pautrier microabscesses are intraepidermal collections of atypical T lymphocytes (cerebriform nuclei) that are pathognomonic of mycosis fungoides (cutaneous T-cell lymphoma).
Question 2: 'Interface dermatitis' describes inflammatory damage primarily at which anatomical site?
- Between the dermis and subcutaneous fat
- At the dermal-epidermal junction (Correct answer)
- Within the mid-dermis
- Between the dermis and follicular epithelium
Correct answer: At the dermal-epidermal junction
Interface dermatitis refers to a lichenoid inflammatory pattern at the dermal-epidermal junction, causing vacuolar change or band-like infiltrate, as seen in lichen planus and lupus.
Question 3: The 'saw-tooth' pattern of rete ridges on skin histology is most characteristic of which condition?
- Psoriasis
- Lichen planus (Correct answer)
- Systemic lupus erythematosus
- Seborrheic dermatitis
Correct answer: Lichen planus
Lichen planus shows irregular, saw-tooth shaped rete ridges with a band-like lymphocytic infiltrate hugging the dermal-epidermal junction.
Question 4: Flame figures in the dermis are classically associated with which dermatological condition?
- Erythema nodosum
- Wells syndrome (eosinophilic cellulitis) (Correct answer)
- Dermatitis herpetiformis
- Granuloma annulare
Correct answer: Wells syndrome (eosinophilic cellulitis)
Flame figures are eosinophilic granular deposits coating collagen fibers, characteristic of Wells syndrome (eosinophilic cellulitis), a recurrent eosinophilic dermatosis.
Question 5: A 'Grenz zone' on dermatopathology refers to which histological finding?
- A band of spared papillary dermis between the epidermis and a dermal infiltrate (Correct answer)
- A clear halo surrounding a tumor nest
- The zone of acanthosis seen in psoriasis
- The normal papillary dermis in unaffected skin
Correct answer: A band of spared papillary dermis between the epidermis and a dermal infiltrate
The Grenz zone is a narrow band of normal papillary dermis separating the overlying epidermis from the underlying inflammatory or neoplastic infiltrate, often seen in lepromatous leprosy and some lymphomas.
Question 6: Acantholysis, the disruption of cell-to-cell adhesion between keratinocytes, is a hallmark histological finding in which condition?
- Epidermolysis bullosa
- Bullous pemphigoid
- Pemphigus vulgaris (Correct answer)
- Dermatitis herpetiformis
Correct answer: Pemphigus vulgaris
Pemphigus vulgaris features intraepidermal acantholysis due to IgG autoantibodies against desmoglein 3, causing suprabasal blisters with 'tombstone' basal cells.
Question 7: Which inflammatory cell type predominates in the histological findings of allergic contact dermatitis?
- Neutrophils
- Plasma cells
- Eosinophils
- Lymphocytes (Correct answer)
Correct answer: Lymphocytes
Allergic contact dermatitis is a type IV (delayed-type) hypersensitivity reaction mediated by T lymphocytes, which predominate in the perivascular dermal infiltrate.
Dermatologist Certificate Dermatopathology and Histology 2
Pautrier microabscesses on skin biopsy are characteristic of which condition?