10 exam-style questions with answers and explanations, straight from our 1,030-question bank. Tap an answer to check yourself. When you're ready, take the scored version in the free practice test.
These 10 free AP questions are organized by exam domain, so you can see how each part of the Certification in Anatomic Pathology blueprint is tested. Reveal the answer and explanation under each question.
Domain 1: Gastrointestinal (includes GI tract, liver, pancreas, gallbladder) 22% of exam
Question 1
A sigmoid colectomy contains an adenocarcinoma extending into pericolic fat. All 19 regional lymph nodes are negative. Three separate carcinoma nodules lie within the regional mesocolic drainage area; none contains residual lymph-node tissue, a vessel wall, or a recognizable nerve. They are discontinuous from the primary tumor. Under AJCC eighth-edition criteria, how should the regional disease be recorded?
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Correct answer: C - pN1c: tumor deposits without regional lymph-node metastasis
Question 2
Resection of an incidentally detected liver mass in a 34-year-old woman shows bland hepatocyte nodules separated by fibrous septa containing malformed arteries and a prominent ductular reaction. A stellate scar is present. Glutamine synthetase stains broad, interconnected, map-like areas rather than the entire lesion uniformly. The surrounding liver is not cirrhotic. What is the unifying diagnosis?
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Correct answer: C - Focal nodular hyperplasia
Question 3
A pancreatic neuroendocrine neoplasm forms orderly trabeculae of relatively uniform cells with finely stippled chromatin. There is no small-cell morphology or confluent necrosis. The mitotic rate is 4 per 2 mm². In the Ki-67 hot spot, 1,000 nucleated cells are counted: 600 are tumor cells and 400 are lymphocytes or stromal cells. Of the tumor cells, 150 have positive nuclei. Which combination correctly integrates the proliferation index with the morphology?
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Correct answer: B - Well-differentiated NET, grade 3; Ki-67 index 25%
Domain 3: Genitourinary (includes male reproductive) 6% of exam
Question 4
One prostate needle core contains acinar adenocarcinoma with three invasive patterns: 65% discrete, well-formed glands; 31% fused and poorly formed glands; and 4% solid nests without lumina. The solid nests are confirmed as invasive carcinoma rather than intraductal carcinoma. What Gleason score and Grade Group belong on this core's report?
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Correct answer: B - Gleason 3 + 5 = 8; Grade Group 4
Domain 4: Endocrine 4% of exam
Question 5
A thyroid lobectomy contains a 2.6-cm encapsulated tumor composed entirely of follicles. The nuclei show enlargement and overlap, grooves, and chromatin clearing. Examination of the entire tumor and capsule reveals no capsular or vascular invasion, well-formed papillae, psammoma bodies, solid growth, necrosis, or mitotic figures. Using the revised 2018 diagnostic criteria, how should this tumor be classified?
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Correct answer: D - Noninvasive follicular thyroid neoplasm with papillary-like nuclear features
Domain 5: Administrative, Inspection, and DO Viewpoint 8% of exam
Question 6
A signed surgical pathology report states that carcinoma involves a resection margin. Review of the slides and dictation confirms that the margin is negative and that the positive wording was a transcription error. The surgeon has scheduled re-excision for the following morning on the basis of that report. Which response best corrects the error while protecting the patient and preserving the medical record?
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Correct answer: C - Notify the surgeon promptly and issue an amended report, preserving the original in the audit trail
Domain 6: Neuropathology 3% of exam
Question 7
The initial sections of a cerebral resection show an infiltrating astrocytic tumor with sparse mitoses and no necrosis or microvascular proliferation. Tumor cells are IDH1 R132H-positive and have lost ATRX. Molecular testing shows retained chromosome arms 1p and 19q but homozygous deletion of CDKN2A/B. Under WHO CNS5, the final integrated diagnosis should be:
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Correct answer: A - Astrocytoma, IDH-mutant, CNS WHO grade 4
Domain 7: Breast 12% of exam
Question 8
HER2 testing of an invasive breast carcinoma yields IHC 2+, a HER2/CEP17 ratio of 2.4, and an average of 3.2 HER2 signals per tumor nucleus. A second observer, blinded to the original count, recounts 30 invasive tumor cells in the corresponding IHC area and obtains the same ISH category. Controls and tissue handling are satisfactory, and there is no separate amplified population or other histopathologic discordance. Using the ASCO/CAP 2018 algorithm reaffirmed in 2023, which final report is appropriate?
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Correct answer: A - HER2-negative, with the explanatory comment for this ISH pattern
Domain 10: Dermatopathology 13% of exam
Question 9
Recurrent tense blisters on the dorsal hands of a 58-year-old leave scars and small milia. A fresh blister shows a subepidermal split with little inflammation. Direct immunofluorescence of perilesional skin demonstrates linear IgG along the basement membrane; indirect immunofluorescence on salt-split skin localizes binding to the dermal floor. Which antigen is the best match for this clinicopathologic pattern?
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Correct answer: B - Type VII collagen
Domain 12: Obstetrical and Gynecologic 13% of exam
Question 10
Products of conception from an early pregnancy loss contain a mixture of enlarged, scalloped villi and smaller villi, with focal trophoblastic proliferation. The findings raise, but do not settle, the possibility of a partial hydatidiform mole. Villous cytotrophoblast and stromal cells retain p57, and the internal controls are satisfactory. Adequate villous and maternal decidual tissue remains available. Which investigation most definitively distinguishes a partial mole from a nonmolar gestation?
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Correct answer: D - Short tandem repeat genotyping of villous tissue compared with maternal tissue