Practice Test GeeksAmerican Board of Pathology (ABPath) Practice Test
← All ABPATH Flashcard Decks

Dermatopathology Flashcards

7 cards from real ABPATH practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Dermatopathology flashcards as text

  1. Which molecular alteration is found in approximately 40–60% of cutaneous melanomas arising on intermittently sun-exposed skin?

    Answer: BRAF V600E mutation

    BRAF V600E mutations occur in approximately 40–60% of cutaneous melanomas, particularly those on intermittently sun-exposed skin, making BRAF the most common actionable driver mutation.

  2. A compound melanocytic lesion shows large epithelioid cells with abundant cytoplasm containing fine 'dusty' melanin pigment arranged in nests, with a pushing border into the deep dermis but no significant atypia or mitoses. This best describes:

    Answer: Deep penetrating nevus

    Deep penetrating nevus is characterized by large epithelioid-to-spindle melanocytes with abundant dusty melanin pigment arranged in nests and fascicles, extending deeply into the dermis with a pushing border but without significant atypia.

  3. The t(X;18)(p11;q11) translocation producing an SS18-SSX fusion gene is the defining molecular alteration of:

    Answer: Synovial sarcoma

    Synovial sarcoma is defined by the t(X;18)(p11;q11) translocation creating SS18-SSX1 or SS18-SSX2 fusion genes, which is diagnostic and found in virtually all cases regardless of morphology.

  4. Donovan bodies (Klebsiella granulomatis within macrophages) in granuloma inguinale are best demonstrated with:

    Answer: Giemsa stain

    Donovan bodies appear as bipolar-staining intracytoplasmic rod-shaped organisms with a 'safety pin' appearance, best demonstrated with Giemsa stain on tissue smears or biopsies.

  5. A skin biopsy from an HIV-positive patient shows lobular capillary proliferation with plump endothelial cells, neutrophils, and granular eosinophilic material best identified by Warthin-Starry stain. This is most consistent with:

    Answer: Bacillary angiomatosis

    Bacillary angiomatosis (caused by Bartonella henselae or B. quintana) shows lobular vascular proliferation with plump endothelial cells, neutrophils, and granular bacterial clumps highlighted by Warthin-Starry stain.

  6. Clark's levels of melanoma invasion differ from Breslow thickness in that Clark's levels classify depth based on:

    Answer: Anatomic skin layers penetrated

    Clark's levels (I–V) classify melanoma invasion by anatomic skin layers penetrated — from in situ (level I) to subcutaneous fat (level V) — unlike Breslow thickness which is an absolute micrometer measurement.

  7. Which immunohistochemical staining pattern is most characteristic of Merkel cell carcinoma and helps distinguish it from metastatic small cell carcinoma of the lung?

    Answer: Dot-like CK20 positivity with TTF-1 negativity

    Merkel cell carcinoma shows a characteristic dot-like (perinuclear) CK20 staining pattern and is TTF-1 negative, distinguishing it from metastatic pulmonary small cell carcinoma which is TTF-1 positive and CK20 negative.