ABPath Dermatopathology

Question 1

Which pattern of inflammation is characterized by lymphocytes lined up along the dermal-epidermal junction with associated vacuolar change and dyskeratotic keratinocytes?

Accepted Answer

Interface

Answer

Interface dermatitis is defined by lymphocytes at the dermal-epidermal junction with vacuolar alteration and dyskeratotic (necrotic) keratinocytes, as seen in lichen planus and lupus.

Question 2

A skin biopsy shows parakeratosis, regular acanthosis with elongated rete ridges, and collections of neutrophils in the stratum corneum (Munro microabscesses). This is most consistent with:

Accepted Answer

Psoriasis

Answer

Psoriasis classically shows Munro microabscesses (neutrophil collections in the stratum corneum), regular acanthosis with elongated rete ridges, and parakeratosis with suprapapillary plate thinning.

Question 3

In a non-ulcerated melanoma, Breslow thickness is measured from:

Accepted Answer

The granular layer to the deepest tumor cell

Answer

Breslow thickness is measured from the top of the granular layer (or the base of an ulcer if ulcerated) to the deepest invasive tumor cell.

Question 4

Which histologic feature best supports a diagnosis of Spitz nevus over melanoma in a pediatric patient?

Accepted Answer

Presence of Kamino bodies

Answer

Kamino bodies — eosinophilic PAS-positive globules at the dermal-epidermal junction — are characteristic of Spitz nevi and are a helpful benign feature distinguishing them from melanoma.

Question 5

A biopsy shows atypical keratinocytes involving the full thickness of the epidermis without dermal invasion. This is best classified as:

Accepted Answer

Squamous cell carcinoma in situ (Bowen disease)

Answer

Full-thickness epidermal atypia without breach of the basement membrane is the hallmark of squamous cell carcinoma in situ, also known as Bowen disease.

American Board of Pathology (ABPath) Practice Test

American Board of Pathology (ABPath) Practice Test

ABPath Dermatopathology