ABPath Dermatopathology Subspecialty Certification Examination Practice Test
Dermatopathology examines skin biopsies by correlating tissue architecture, cellular features, and clinical presentation. The practice material samples melanocytic lesions, keratinocytic patterns, adnexal tumors, cutaneous lymphoid proliferations, interface dermatitis, and inflammatory infiltrates, with emphasis on distinguishing entities that can look similar on routine sections.
Exam overview
About the ABPath Dermatopathology Subspecialty Certification Examination Exam
Interpretation requires recognizing epidermal reaction patterns such as psoriasiform hyperplasia, lichenoid or vacuolar interface change, and neutrophilic scale, then integrating dermal findings such as mucin, sclerosis, granulomas, or vascular injury. Tumor assessment involves evaluating architecture, cytology, depth, and lineage markers—for example, separating adnexal neoplasms by ductal differentiation or classifying a lymphoid proliferation with immunophenotypic evidence. These diagnostic tasks also require judging whether a microscopic pattern supports a specific disease or only a broader inflammatory category, and correlating stain results with morphology rather than treating an isolated marker as definitive.
Sample Practice Questions
Review a selection from this exam's published US Practice Tests practice bank.
A biopsy of a pearly papule shows a dermal neoplasm composed of small ducts and cords of epithelial cells in a densely sclerotic stroma. The tumor extends into the deep dermis. Which diagnosis should be considered?
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Correct answer: AMicrocystic adnexal carcinoma is an infiltrative adnexal carcinoma that may show superficial keratin-filled cysts and deeper ductal structures in desmoplastic stroma, with extension into deep dermis or subcutis. This deep infiltrative pattern distinguishes it from many benign adnexal mimics.
A biopsy from a patient with a rapidly spreading eruption shows regular psoriasiform epidermal hyperplasia, diminished granular layer, confluent parakeratosis containing neutrophils, and dilated papillary dermal capillaries. Which diagnosis is most consistent with these findings?
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Correct answer: ARegular psoriasiform hyperplasia, hypogranulosis, neutrophils within parakeratotic scale, and dilated papillary dermal vessels form a classic histologic pattern of psoriasis.
A skin biopsy from a patient with a photosensitive eruption shows vacuolar interface change, scattered apoptotic keratinocytes, basement membrane zone thickening, and increased dermal mucin. Which diagnosis is most consistent with this combination?
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Correct answer: ACutaneous lupus erythematosus can show vacuolar interface dermatitis, apoptotic keratinocytes, thickening of the basement membrane zone, and increased dermal mucin. The other choices have different dominant patterns, such as psoriasiform hyperplasia, spongiosis, or palisading granulomatous inflammation.
A punch biopsy from a patient with chronic pruritic plaques shows compact hyperkeratosis, irregular psoriasiform epidermal hyperplasia, hypergranulosis, and vertically oriented papillary dermal collagen. What is the most likely diagnosis?
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Correct answer: ALichen simplex chronicus reflects chronic rubbing or scratching and commonly shows compact hyperkeratosis, irregular epidermal hyperplasia, hypergranulosis, and vertically oriented collagen in the papillary dermis. The other options have distinct patterns, including spongiosis or pustule formation.
A biopsy of a pigmented lesion shows nests of melanocytes at the dermoepidermal junction. The rete ridges are elongated, and melanocytes are present at the tips of adjacent rete ridges, creating bridges between them. Which benign melanocytic lesion is most compatible with this architecture?
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Correct answer: AA junctional nevus is composed of melanocytic nests along the dermoepidermal junction. Bridging of adjacent rete ridges by junctional nests is a common architectural feature of acquired nevi and, by itself, does not establish malignancy.
A biopsy from a patient with a solitary cutaneous nodule shows a sharply circumscribed dermal tumor composed of two populations of cells forming duct-like structures, with a dense lymphocytic background. Which diagnosis is most likely?
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Correct answer: AEccrine spiradenoma typically forms a well-circumscribed dermal nodule with basaloid cells of differing sizes, ductal structures, and a conspicuous lymphocytic infiltrate. The other options have distinct fibrohistiocytic, matrical, or smooth-muscle morphology.
A biopsy from a patient with a solitary enlarging red-brown papule shows a well-circumscribed dermal proliferation of large mononuclear cells and multinucleated giant cells with abundant eosinophilic cytoplasm. The cells express CD68 and factor XIIIa. What is the most likely diagnosis?
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Correct answer: AJuvenile xanthogranuloma is a benign histiocytic lesion composed of lipidized mononuclear cells and Touton-type giant cells; it commonly expresses histiocytic markers such as CD68 and factor XIIIa.
How to use this practice test
The free practice bank contains 50 published questions. Each session presents up to 20 random questions, and results appear after the session. Use the cases to test pattern recognition, differential diagnosis, and interpretation of immunohistochemical findings; revisit missed items by identifying which morphologic or ancillary clue changed the diagnosis.
Preparation tips
- For each inflammatory case, name the dominant reaction pattern first, then connect details such as granular-layer change, parakeratosis, interface injury, or dermal mucin to a focused differential.
- Compare adnexal tumors by architecture and differentiation, including ducts, cords, sebocytes, stromal sclerosis, and any accompanying lymphocytic background.
- Practice distinguishing melanocytic architecture by junctional nesting, rete-ridge configuration, bridging, and the distribution of melanocytes.
- Interpret immunostains in context: pair lineage markers such as CD20 or CD3, and histiocytic markers such as CD68 or factor XIIIa, with the cell morphology and growth pattern.
- When evaluating a neutrophil-rich biopsy, assess vessel-wall integrity and fibrinoid necrosis before diagnosing vasculitis.