ABD Study Guide 2026
Everything you need to pass the ABD exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 ABD Exam Format at a Glance
📚 ABD Topics to Study (69)
✍️ Sample ABD Questions & Answers
1. According to the American Joint Committee on Cancer (AJCC) 8th edition staging system for melanoma, which of the following findings defines a primary tumor as stage T1b?
The AJCC 8th edition revised the T1 criteria. A T1a melanoma is defined as being <0.8 mm thick without ulceration. A T1b melanoma is defined as either being <0.8 mm thick with ulceration OR being 0.8-1.0 mm thick, with or without ulceration. Mitotic rate is no longer used for T1 sub-categorization.
2. A cutaneous tumor shows peripheral palisading of basaloid cells with clefting (retraction) from the surrounding stroma. What is the diagnosis?
Peripheral palisading of basaloid nests with stromal retraction artifact is characteristic of basal cell carcinoma.
3. Perioral and acral mucocutaneous lentigines in Peutz-Jeghers syndrome result from germline mutations in which gene?
Peutz-Jeghers syndrome is caused by autosomal dominant germline mutations in STK11 (LKB1), encoding a serine-threonine kinase tumor suppressor on chromosome 19p13, leading to mucocutaneous lentigines and hamartomatous gastrointestinal polyps.
4. Why is it important to read peer-reviewed dermatology journals?
Peer-reviewed dermatology journals are critical resources for dermatologists because they publish research findings, clinical trials, and reviews that have been rigorously evaluated by experts in the field. This ensures that the information is evidence-based, allowing practitioners to stay current with the latest advancements, best practices, and treatment guidelines, ultimately improving patient care.
5. Langerhans cells in the epidermis are best characterized by the presence of which cytoplasmic organelle?
Birbeck (tennis-racket) granules are the ultrastructural hallmark of Langerhans cells.
6. A child has multiple dome-shaped umbilicated papules on the trunk. What is the causative agent?
Molluscum contagiosum is caused by a poxvirus and produces umbilicated papules.