Dermatologist Certificate Dermatopathology and Histology 1 — Questions and Answers
Question 1: Which histological finding is considered pathognomonic of psoriasis?
- Munro microabscesses (Correct answer)
- Pautrier microabscesses
- Civatte bodies
- Flame figures
Correct answer: Munro microabscesses
Munro microabscesses are collections of neutrophils within the parakeratotic stratum corneum and are pathognomonic of psoriasis.
Question 2: In which epidermal layer are melanocytes primarily located?
- Stratum corneum
- Stratum granulosum
- Stratum spinosum
- Stratum basale (Correct answer)
Correct answer: Stratum basale
Melanocytes reside in the stratum basale (basal layer), where they synthesize melanin and transfer it to surrounding keratinocytes via dendrites.
Question 3: In dermatopathology, 'spongiosis' refers to which histological finding?
- Thickening of the stratum corneum
- Intercellular edema within the epidermis (Correct answer)
- Loss of cell-to-cell cohesion in the epidermis
- Thinning of the granular layer
Correct answer: Intercellular edema within the epidermis
Spongiosis is intercellular edema between keratinocytes, causing the epidermis to appear sponge-like on histology and is the hallmark of eczematous dermatitis.
Question 4: Civatte bodies (colloid/hyaline bodies) are characteristic of which dermatological condition?
- Psoriasis
- Lichen planus (Correct answer)
- Pemphigus vulgaris
- Dermatitis herpetiformis
Correct answer: Lichen planus
Civatte bodies are apoptotic keratinocytes (eosinophilic globules) seen at the dermal-epidermal junction in lichen planus due to interface dermatitis.
Question 5: Subepidermal blisters with neutrophilic microabscesses in dermal papillae are histologically characteristic of which condition?
- Bullous pemphigoid
- Pemphigus vulgaris
- Dermatitis herpetiformis (Correct answer)
- Linear IgA bullous dermatosis
Correct answer: Dermatitis herpetiformis
Dermatitis herpetiformis shows subepidermal blisters with neutrophil-rich microabscesses at dermal papillae tips, corresponding to granular IgA deposits.
Question 6: Parakeratosis is defined as which histological finding?
- Absence of the stratum granulosum
- Retention of nuclei within the stratum corneum (Correct answer)
- Increased thickness of the stratum spinosum
- Neutrophil infiltration within the epidermis
Correct answer: Retention of nuclei within the stratum corneum
Parakeratosis is the retention of nuclei in the stratum corneum, indicating abnormal keratinization and rapid epidermal turnover, as seen in psoriasis.
Question 7: Which histological feature best distinguishes superficial spreading melanoma from a benign compound nevus?
- Presence of dermal melanocytes
- Pagetoid spread of melanocytes into upper epidermal layers (Correct answer)
- Nesting of melanocytes at the dermal-epidermal junction
- Presence of melanin pigment
Correct answer: Pagetoid spread of melanocytes into upper epidermal layers
Pagetoid spread refers to single melanocytes or nests ascending into the upper epidermis, a hallmark of melanoma not seen in benign nevi.
Dermatologist Certificate Dermatopathology and Histology 1
Which histological finding is considered pathognomonic of psoriasis?